Physics 221 Final test 2

Both the disk and the ring have the same mass, and the same radius. Which has the larger moment of inertia about the center?

the ring

A 104 N car is lifted by a manually operated hydraulic lift. The area of the shaft of the lift is 80 cm2; the area of the piston that forces liquid into the system is 2 cm2. What minimum force must be exerted on this piston to lift the car? 104 N 125 N 250 N 62.5 N 5000 N

250 N

An object is dropped from rest at t = 0 into a viscous fluid. Which of the following best describes the object's speed as a function of time? practice2_q15.gif (a) (b) (c) (d) none of these

(b)

The radius of the aorta is ~ 10 mm = 10-2 m and the blood flowing through it has a speed ~ 300 mm/s = 0.3 m/s. A capillary has a radius ~ 4×10-3 mm = 4×10-6 m, but there are literally billions of them. The average speed of blood through the capillaries is ~ 5×10-4 m/s. (i) Calculate the effective cross sectional area of the capillaries and (ii) the approximate number of capillaries. (i) 0.06 m2, (ii) 1.2*109 (i) 0.188 m2, (ii) 3.75*106 (i) 0.06 m2, (ii) 3.75*1010 (i) 0.3 m2, (ii) 4*106 (i) 0.188 m2, (ii) 3.75*109

(i) 0.188 m2, (ii) 3.75*109

Two carts on an air track are pushed towards each other. Initially, cart 1 moves in the positive x direction and cart 2 moves in the negative x direction. They bounce off each other elastically. The graphs at the right describe some of the variables associated with the motion as a function of time. For the experiment described and for each item in the list below, identify which graph is a possible display of that variable as a function of time. If none apply, choose N (for none). (i) the momentum of cart 1 (ii) the position of cart 1. (iii) the position of cart 2. (i) B, (ii) D, (iii) A (i) D, (ii) B, (iii) N (i) D, (ii) N, (iii) B (i) F, (ii) A, (iii) D (i) B, (ii) E, (iii) C

(i) D, (ii) B, (iii) N

A centrifuge in a medical laboratory rotates at an angular speed of 3600 rev/min. When switched off, it rotates 50 times before coming to rest. What is the constant angular acceleration of the centrifuge? -129600/s2 -113.1/s2 -226.2/s2 -36/s2 -5.73/s2

-226.2/s2

Blood and water have the same contact angle with glass. The density of blood is 5% higher than that of water. (ρblood= 1.05 ρwater) While you make your capillary action measurements you find that water rises in the same tube a factor 1.69 higher than a blood sample. The surface tension of water at the same temperature is 0.073 N/m. What is the surface tension of the blood sample? 0.045 N/m 0.117 N/m 0.073 N/m 0.105 N/m

0.045 N/m

A 40 kg child standing on a frozen pond throws a 0.5 kg stone to the east with a speed of 5 m/s. Neglecting friction between the child and the ice, what is the recoil velocity of the child? 5 m/s west 5 m/s east 0.0625 m/s west 0.25 m/s west 0.0125 m/s east

0.0625 m/s west

A 5.00 kg mass sliding along a horizontal frictionless surface at 2.00 m/s collides with a 1.00 kg stationary mass. After the collision the two masses stick together and contact a light Hooke's-law spring with spring constant k = 1000 N/m. What is the maximum compression (in m) of the spring? 0.14 m 0.02 m 0.01 m 0.016 m 0.13 m

0.13 m

An intravenous blood plasma drip enters a vein in the patient's arm from a bag raised a height h above the vein. If the diameter of the 5 cm long needle is 0.5 mm, use Poiseuille's law to find the height h that results in a 5 cm3/min flow rate. (Assume the blood pressure in the arm is 18 torr = 2392 Pa and the viscosity of the blood plasma is 1.5*10-3 Pa-s, and the density is same as water) 0.17 m 1.55 m 6.46 m 0.52 m 0.66 m

0.66 m

A 90 kg man and a 10 kg girl are initially 10 m apart. They are connected by a massless rope, and are sitting on a frictionless horizontal surface. The man pulls on the rope until they meet. Where do they meet? At the initial position of the man (i.e., he does not move at all). 1 m away from the initial position of the man. At the mid-point between man and the girl. 1 m away from the initial position of the girl.

1 m away from the initial position of the man

You have a mass of 60 kg. You are standing on an icy pond, when your "friend" throws a 10 kg ball at you with horizontal velocity of 7 m/s.If you catch the ball, how fast will you be moving?

1 m/s

When the body requires an increased blood flow rate in a particular organ or muscle, it can accomplish this by increasing the diameter of arterioles on that area. By what factor must the diameter of an arteriole increase to double the volume flow rate of blood, all other factors remaining the same? 2 16 1.41 1.19 This cannot be accomplished by increasing the diameter.

1.19

Two particles of masses 2 g and 8 g are separated by a distance of 6 cm. The distance of their center of mass from the heavier particle is

1.2 cm

Two glass marbles of radii r and 2r fall through a high-viscosity fluid. What is the ratio of their terminal velocities vr/v2r?

1/4

Two blocks of mass M and 3 M are placed on a horizontal frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them. A cord holding them together is burned, after which the block of mass 3 M moves to the right with a speed of 5 m/s. What is the speed of the block of mass M? 5/3 m/s to the left 15 m/s to the right 1/3 m/s to the right 1/3 m/s to the left 15 m/s to the left

15 m/s to the left

A 2 kg block of wood is floating in water. What is the magnitude of the buoyant force acting on the block? 0 2 kg Correct! 19.6 N 2000 N It cannot be determined since we do not know the density of the wood.

19.6 N

A bicycle's wheels have a radius of 33 cm. The bicycle is traveling at a speed of 6.5 m/s. What is the angular speed of the front tire? 0.197 rad/s 1.24 rad/s 5.08 rad/s 19.7 rad/s 215 rad/s

19.7 rad/s

A 1 kg rock is suspended by a massless string from one end of a meter stick at the 0 cm mark. What is the mass m suspended from the meter stick at the 75 cm mark if the system is balanced? 0.25 kg 0.5 kg 1 kg 2 kg 4 kg

2 kg

A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 seconds, the angular velocity decreases to 200 rev/min. Assuming the angular acceleration is constant, how many revolutions does the blade undergo during this time? 10 20 125 100 1200

20

A ball (mass 0.40 kg) is initially moving to the left at 30 m/s. After hitting the wall, the ball is moving to the right at 20 m/s. What is the impulsethat the ball receives during its collision with the wall?

20 kg m/s to the right

The brake system in most cars makes use of a hydraulic system. This system consists of a fluid filled tube connected at each end to a piston. Assume that the piston attached to the brake pedal has a cross sectional area of 0.5 in2and the piston attached to the brake pad has a cross section area of 2in2. When you apply a force of 10 pounds to the piston attached to the brake pedal, the force at the brake pad will be

40 lbs

Mercury has an unusually large surface tension γ = 0.465 N/m. Calculate the excess pressure inside a drop of mercury 4 mm in diameter. 0.23 Pa 465 Pa 233 Pa 1.23 kPa 0.11 kPa

465 Pa

Mercury has an unusually large surface tension γ= 0.465 N/m. Calculate the excess pressure inside a drop of mercury 4 mm in diameter.

465 Pa

A piece of clay with mass m = 0.01 kg collides with the floor at speed of 8 m/s and sticks. The collision takes 0.02 s. The magnitude of the average force the piece of clay experiences during the collision is

4N

An object rotates initially with a period of 1.0 s. It accelerates with constant angular acceleration for 10 s. Its final rotation period is 0.1 s. What was the magnitude of its angular acceleration? 0.9 rad/s2 9 rad/s2 18.25 rad/s2 5.65 rad/s2 0.12 rad/s2

5.65 rad/s2

You can chew through very tough objects with your incisors because they exert a large force on the small area of a pointed tooth. What pressure in MPa can you create by exerting a force of 500 N with your tooth on an area of 1.00 mm2? Enter an integer.

500

A beaker containing 5.0 kg of water is on a weighing scale. A 0.8 kg block of metal that has density 8*103 kg/m3 that is attached to a string is lowered completely into water without touching the bottom. Assume that the beaker is massless, and water has density 103 kg/m3, and g = 10 m/s2. What is the reading on the scale? 49 N 50 N 51 N 52 N 5 N

51 N

A CD spins at 5500 rpm (revolutions per minute). What is its angular speed in units of rad/s or s-1? 5500 576 92 875 25

576

A 50 kg woman balances on one heel of a high-heel shoe. If the heel is circular with radius 0.5 cm, what pressure does she exert on the floor? 50 kg 500 N 1000 Pa 6.2 MPa 6.37*105 Pa

6.2 MPa

A horizontal pipe, 10 cm in diameter, has a smooth reduction to a pipe 5 cm in diameter. If the pressure of the water in the larger pipe is 8.00104 Pa and the pressure in the smaller pipe is 6.00104 Pa, what is the flow speed of the water (in m/s) in the smaller pipe? 0.0625 m/s 6.53 m/s 0.94 m/s 42.67 m/s 2 m/s

6.53 m/s

A 2 kg mass is at x = 0 m, y = 2 m, and a 3 kg mass is at x = 2 m, y = 0 m. The x- and y-coordinates, respectively, of the center of mass of this system are 1 m, 1 m 2/5 m, 2/5 m 0 m, 0 m 2m, 2 m 6/5 m, 4/5 m

6/5 m, 4/5 m

How much negative pressure, with respect to atmospheric pressure, do your lungs have to produce, so you can you suck water through a straw to a height of 8 cm?

800 Pa

A soap bubble with radiusof 3.0 cm is floating in air. What is the pressure difference across the two surfaces of the bubble? The surface tension of soapy water is γ = 69 * 10-3N/m.

9.2 N/m2

Fluid is flowing from left to right through the pipe. Points A and B are at the same height, but the cross-sectional areas of the pipe differ. Points B and C are at different heights, but the cross-sectional areas are the same. Rank the pressures at the three points, from highest to lowest. A and B (a tie), C C, A and B (a tie) B, C, A C, B, A A, B, C

A, B, C

Consider two carts, of masses m and 2m, at rest on an air track. You push on each cart for 3 s, exerting equal force Fnet on each. After the push, the momentum of mass m is 1/2 the momentum of mass 2m. After the push, the momentum of mass m is twice the momentum of mass 2m. After the push, the momentum of mass m is four times the momentum of mass 2m. After the push, the momentum of mass m is 1/4 the momentum of mass 2m. After the push, the momentum of mass m is the same as the momentum of mass 2m.

After the push, the momentum of mass m is the same as the momentum of mass 2m.

The picture below shows 5 blocks. The blocks have equal volumes but different masses. The blocks are placed in an aquarium tank filled with water and blocks 2 and 5 come to rest as shown in the figure. Which answer is correct? Block 1 will come to rest in the same position as block 2. Block 3 will come to rest in the same position as block 5. Block 3 will come to rest at a depth half way between block 2 and 5. It is impossible to predict where blocks 3 and 4 will come to rest.

Block 3 will come to rest in the same position as block 5.

Two objects, A and B, have the same volume and are completely submerged in a liquid, although A is deeper than B.Which object, if either, experiences the greater buoyant force?

Both objects experience the same buoyant force.

An object moves with constant speed in the clockwise direction along the circular path shown below. At the point indicated by the black dot, in which direction is the angular velocity vector ω pointing? A B C D None of these.

D into the paper

F1, F2and F3have the same magnitude. Which statement is correct?

F1produces the torque with the largest magnitude

Modeling a meter stick as a forearm, compare the force FB that the biceps has to exert to keep the forearm horizontal to the weight of the forearm FW = mg. Let d = 10 cm and the distance from where the biceps muscle attached to the center of mass be d' = 40 cm. FB = 5 mg FB = mg FB = 4 mg FB = 2 mg FB = 3 mg

FB = 5 mg

In soap box car races, the cars are boxes with wheels. They begin at rest at the top of a hill, and at the start of the race they all begin rolling down the hill. The soap box car that reaches the bottom of the hill first is the winner. You have entered a soap box car race where the rule is that all the wheels and cars must have equal mass. Since you have taken Physics, you know that it is worse to have wheels with spokes (where the mass is mostly on the rim) rather than solid wheels because The solid wheels are easier to paint. The solid wheels have a higher rotational mass or moment of inertia and therefore will retain more rotational energy. Given the same torque, the wheels with spokes have a higher rotational mass or moment of inertia and therefore will have a greater angular acceleration. Given the same torque, the wheels with spokes have a higher rotational mass or moment of inertia and therefore will have a smaller angular acceleration. Given the same amount of energy, too small a fraction is converted into rotational kinetic energy of the wheels.

Given the same torque, the wheels with spokes have a higher rotational mass or moment of inertia and therefore will have a smaller angular acceleration.

Consider two masses, each of size 2m at the ends of a light rod of length L with the axis of rotation through the center of the rod. The rod is doubled in length and the masses are halved. Compare IA and IB. IA > IB IA < IB IA = IB To determine the relationship between IA and IB we would have to know the exact value of m in kg.

IA < IB

Suppose you are riding on a merry - go - round and you move out to the edge. What happens to the rotational rate of the system? It decreases because there is a net force on the entire system, slowing it down. It increases because there is a net force on the entire system, speeding it up. It decreases because angular momentum is conserved and the moment of inertia increases. It increases because angular momentum is conserved and the moment of inertia increases. It decreases because angular momentum is conserved and the moment of inertia decreases.

It decreases because angular momentum is conserved and the moment of inertia increases.

The fundamental dimensions of pressure are M L-2 T-2 M L-3 M L T-2 M L T-1 M L-1 T-2

M L-1 T-2

Which of the following statements is false? An aneurysm in an artery leads to a locally elevated blood pressure. Plaque deposit on an artery or arteriole wall leads to a decreased local blood pressure. Plaque deposit on an artery or arteriole wall can lead to the collapse of that vessel. Plaque deposit on an artery or arteriole wall causes an increase in local blood pressure and can lead to bursting of that vessel. The speed of the blood increases as it moves through a region of an artery with plaque deposit.

Plaque deposit on an artery or arteriole wall causes an increase in local blood pressure and can lead to bursting of that vessel.

A DVD is rotating with an ever increasing speed. How do the angular velocity, angular acceleration, tangential velocity, and tangential acceleration compare at points P and Q? Points P and Q have the same angular velocity but point Q has a larger angular acceleration. Points P and Q have the same angular velocity and the same angular acceleration. Points P and Q have the same tangential velocity and the same tangential acceleration. Point Q has a larger tangential acceleration but points P and Q have the same tangential velocity. Angular velocity, angular acceleration, tangential velocity, and tangential acceleration are larger for point Q than for point P.

Points P and Q have the same angular velocity and the same angular acceleration.

In a stationary homogeneous liquid near the surface of Earth, which of the following is true? Pressure is the same at all points independent of depth. Pressure depends on the direction. Pressure is independent of any atmospheric pressure on the upper surface of the liquid. Pressure is the same at all points at the same height. Pressure is largest near the top of the liquid

Pressure is the same at all points at the same height.

Consider a rod of uniform density with an axis of rotation through its center and an identical rod with the axis of rotation through one end. Which has the larger moment of inertia about its axis of rotation? Rod B with the axis through one end. Rod A with the axis through its center. They are identical rods, so they have the same moment of inertia. Not enough information is given to decide. We need to know how fast the rods are rotating.

Rod B with the axis through one end.

A block and a rod are joined together. Each object is of uniform density. The center of mass of the combined object is at the position shown by the "X." Which has the greater mass, the block or the rod? The block has the greater mass. The rod has the greater mass. The block and the rod have the same mass. Not enough information is given to decide.

The block has the greater mass.

Suppose you work in the E.R. and a choking patient comes in with their trachea obstructed. The diameter is 1/3 of what it was before the obstruction. You manage to correct the problem and send them on their way safely, explaining that such obstructions are particularly dangerous because

The blocked airway passes only 1/81 the regular amount of air.

It is correct to say that impulse is equal to momentum. the change in momentum. the force multiplied by the distance the force acts. work. none of the above.

The change in momentum.

Determine the character of the collision. The masses of the blocks, and the velocities before and after are given. The collision is completely inelastic. The collision is perfectly elastic. The collision is partially inelastic. The collision is characterized by an increase in kinetic energy. The collision is not possible because momentum is not conserved.

The collision is not possible because momentum is not conserved.

A bass has a gas-filled sac or air bladder that allows it to float motionless below the surface of the water. What is the bass's average density? Lower than the density of water. The density of water. Higher than the density of water. Its density increases with depth. Its density decreases with depth.

The density of the water.

An ideal, non-compressible fluid is used in the system of pipes shown below. The cross sectional area of pipe 1 is 4 m2, that of pipe 2 is 3 m2, and that of pipe 3 is 2 m2. The fluid enters pipe 1 at 2 m/s, and leaves pipe 2 at 3 m/s. What is the speed of the fluid in pipe 3 and in which direction does it flow? The fluid enters pipe 3 (upward) with speed 1 m/s. The fluid leaves pipe 3 (downward) with speed 1 m/s. The fluid enters pipe 3 (upward) with speed 0.5 m/s. The fluid leaves pipe 3 (downward) with speed 0.5 m/s. The fluid enters pipe 3 (upward) with speed 2 m/s. The fluid leaves pipe 3 (downward) with speed 2 m/s.

The fluid leaves pipe 3 (downward) with speed 0.5 m/s.

Suppose that there is a partial blockage of the aorta, which normally pumps about 5 L of blood per minute. If the diameter of the aorta were reduced by 30%, what increase in blood pressure gradient would be needed to obtain the normal flow rate? (Assume that Poiseuille's law applies.) The pressure gradient would have to increase by a factor of 3.3. The pressure gradient would have to increase by a factor of 1.4. The pressure gradient would have to increase by a factor of 4.2. The pressure gradient would have to increase by a factor of 123. The pressure gradient would have to increase by a factor of 2.

The pressure gradient would have to increase by a factor of 4.2.

Blood flows through a section of a horizontal artery that is partially blocked by a deposit along the artery wall. A hemoglobin molecule moves from the narrow region into the wider region. What happens to the pressure acting on the molecule as it moves from the narrow to the wider region? The pressure decreases. There is no change in the pressure. The pressure increases.

The pressure increases.

Compared to a gear tooth on the rear sprocket (on the left, of small radius) of a bicycle, a gear tooth on the front sprocket (on the right, of large radius) has a slower linear speed and the same angular speed. the same linear speed and a slower angular speed. a faster linear speed and a faster angular speed. the same linear speed and a faster angular speed. none of the above.

The same linear speed and a slower angular speed.

Two bubbles are connected by a hollow tube plus a valve. What will happen once the valve between the two is opened?

The small bubble will drain into the big bubble.

In your dorm room you watch the Vols play in an out-of-town game. It is a cliff hanger and the winner will be determined in the last few seconds of play. Everybody is taking their bathroom break right after the game ends. As the toilets flush and hands are washed, the faucet pressure is noticeably reduced, even though the supply pipe to the rooms can carry all the water needed. Why?

The water has to speed up in the supply pipe and therefore the pressure drops in the pipe.

During a July 4th firecracker party, a pop bottle rocket lying still on the ground explodes, sending fragments everywhere. If the momentum of the pop bottle rocket (ignore friction!) initially at rest is conserved during an explosion, what can be said about the kinetic energy of various fragments after the collision? The kinetic energies of the various parts of the system are individually conserved. The sum of all the kinetic energies of the various pieces equals what it was originally. The total kinetic energy afterwards is less than what it was initially. The total kinetic energy afterwards is greater than what it was initially. Statement b, c, or d could be true, depending on the type of explosion.

The total kinetic energy afterwards is greater than it was initially.

Which of the following assumptions is not made in the derivation of Bernoulli's equation? Streamlines do not cross. There is negligible viscosity. There is negligible friction. There is no turbulence. There is negligible gravity.

There is negligible gravity.

Why do elastic balls bounce so well?

They store energy through compression, like a spring.

Dimples on a golf ball hit without spin result in purely laminar flow. increase drag. reduce drag. are merely decorative.

reduce drag.

A boat floating in a lake contains a block of volume V0. The density of the block is 5000 kg/m3. If the block is thrown overboard, the volume of the water displaced by the block is 5V0. 4V0. V0. V0/5. 0.

V0

Suppose you are on a cart, initially at rest on a frictionless, horizontal track. You throw a series of identical balls against a wall that is rigidly mounted to the cart. If the balls are thrown at a steady rate and bounce straight back, is the cart put into motion?

Yes, it starts to move to the left and steadily gains speed.

Consider three drinking glasses. All three have the same area base, and all three are filled to the same depth with water. Glass A is wider at the top than at the bottom, glass B is cylindrical and so holds less water than A. Glass C is narrower at the top than at the bottom, and so holds less water than B. Which glass has the greatest liquid pressure at the bottom?

all have equal pressure at the bottom

You have heard the tried and true phrase "it is like running in to a brick wall". Now it is time to dig a little deeper and modify the phrase. Assume you are in a car driving and come in contact with this proverbial brick wall. Your car can do three things after the strike: it can go through, come to stop or bounce back. Select the option which will be the most dangerous to you assuming similar collision times.

bouncing back

When water flows smoothly in a straight hose, its viscosity causes the water to

convert some of its kinetic energy into thermal energy.

Two identical carts labeled A and B are initially resting on an air track. The coordinate system for describing the system is shown. The cart on the right, cart B is given a push to the left and is released. The clock is then started. At t = 0, cart B moves in the direction shown with a speed v0. They hit and stick to each other. The graphs below describe some of the variables associated with the motion as a function of time. For the experiment described and for each item in the list below, identify which graph is a possible display of that variable as a function of time assuming a proper scale. "The system" refers to carts A and B together. (i) the momentum of cart A (ii) the momentum of cart B (iii) the total momentum of the system (iv) the total kinetic energy of the system a. (i) #1, (ii) #2, (iii) #3, (iv) #4 b. (i) #1, (ii) #3, (iii) #5, (iv) #2 c. (i) #2, (ii) #3, (iii) #5, (iv) #6 d. (i) #1, (ii) #3, (iii) #6, (iv) #2 e. (i) #4, (ii) #3, (iii) #6, (iv) #1

d. (i) #1, (ii) #3, (iii) #6, (iv) #2

Two moving objects have masses m1 and m2, respectively. If m2 = 4m1, and both have the same kinetic energy, which has more momentum?

object 2 with mass m2

Detergents or wetting agents

reduce the angle of contact

A drum major is given two batons, one gold and one plastic. He is told that both batons have the same mass. He tries spinning each one and finds that the plastic one is much easier to start and stop spinning. He correctly concludes that the plastic baton, in comparison to the gold baton has more of its mass distributed towards the center. has more of its mass distributed towards the ends. must weigh more. must weigh less.

has more of its mass distributed toward the center.

During a football game the ball is kicked and it travels across the field. If the ball is kicked away from its center of mass it will only have translational motion. only have rotational motion. only have vibrational motion. have translational and rotational motion.

have translational and rotational motion.

A man, with his arms at his sides, is spinning on a light frictionless turntable. When he extends his arms his angular velocity increases. his angular velocity remains the same. his moment of inertia decreases. his angular momentum decreases. his angular momentum remains the same.

his angular momentum remains the same.

Consider a block of wood floating on water. If you push down on the top of the block untilit is completely submerged, the buoyant force on it

increases

Rockets receive their forward propulsion through

pushing against the exhaust

The SI units for viscosity are kg/(m-s) kg-m2/s kg-m/s kg-s/m kg-m2/s2

kg/(m-s)

The density of freshwater is 1 g/cm3and the density of seawater is 1.03 g/cm3. A ship will float

lower in freshwater than in seawater.

A person sips a drink through a straw. At which of the following three positions is the pressure lowest? I. Inside the person's mouth II. At the surface of the drink III. At the bottom of the drink only at position I only at position II only at position III both at positions I and III both at positions I and II

only at position I

You can balance a broom on your hand if you're careful. To do this trick well, you must look at your hand. the top of the broom. the broom's center of gravity. the middle of the broom.

the broom's center of gravity.

Compare the flight of two golf balls given the same impulse by the club. Which ball will travel a larger distance?

the dimpled ball

After clearing the bar on a high jump, you land softly on a giant mattress. Landing on a mattress is more comfortable than landing on a sand heap of equal size because

the force the mattress exerts on you to stop your descend is much less than the force the sand heap would exert on you

A sphere, a hoop, and a cylinder, all with the same mass M and the same radius R, are rolling along, all with the same speed v. Which has the most total kinetic energy?

the hoop

A baseball bat with uniform density is cut at the location of its center of mass as shown in the figure. The piece with the smaller mass after the cut is

the piece on the left

Blood flows through a section of a horizontal artery that is partially blocked by a deposit along the artery wall. A hemoglobin molecule moves from the narrow region into the wider region. What happens to the pressure acting on the molecule as it moves from the narrow into the wider region?

the pressure increases

A beaker is filled with water to the rim. Gently you place a toy duck in the beaker and some of the water spills out. The duck floats. The weight of the beaker with the duck floating in it is greater than its weight before adding the duck. less than its weight before adding the duck. the same as its weight before adding the duck. greater or less than its weight before adding the duck, depending on the weight of the duck.

the same as its weight before adding the duck.

When blood flows through into an aneurysm the speed decreases and the pressure increases. the speed increases and the pressure increases. the speed decreases and the pressure decreases. the speed increases and the pressure decreases.

the speed decreases and the pressure increases.

A pocket watch and Big Ben are both keeping perfect time. Which minute hand has the larger angular speed ω?

they both have the same w

A scuba diver descends to a depth of 20 m. At that depth, the pressure is approximately atmospheric pressure. twice atmospheric pressure. three times atmospheric pressure. five times atmospheric pressure. twenty times atmospheric pressure.

three times atmospheric pressure.

The graph shows the acceleration of a cart with mass m = 0.555 kg, moving initially with constant speed, as a function of time, as a force F = ma stops the cart. Estimate the initial momentum of the cart in units of kgm/s. ~2 ~10 ~0.6 ~21 ~5

~0.6

A water pump generates a constant flow Q, which is causing a turbulent spray (Reynolds number R = 3200) out of this cylindrical nozzle:Which of the following three nozzles could be substituted toachieve a streamline flow (R < 2000)?

tube 1 &3

A disk is spinning with angular velocity ωas shown. It begins to slow down. While it is slowing, what are the(i) directions of its angular velocity ω (ii) and its angular acceleration α?

up, down

The four things that affect the amount of water flowing through a hose are air viscosity, hose length, inlet and outlet pressure difference, and hose diameter. water viscosity, hose composition, inlet and outlet pressure difference, and hose diameter. water viscosity, hose length, inlet pressure only, and hose diameter. water viscosity, hose length, inlet and outlet pressure difference, and hose composition. water viscosity, hose length, inlet and outlet pressure difference, and hose diameter.

water viscosity, hose length, inlet and outlet pressure differences, and hose diameter.

Two carts A and B are moving towards each other as shown in the diagram. They collide and come to rest at the point of impact. From this observation we can conclude that the carts

were moving with momenta equal in magnitude and opposite in direction

A man jumps off of a bridge towards a river below. As he falls, he feels himself spinning forward (clockwise in diagram). To keep from hitting the water head-first, the man should windmill his arms counter-clockwise to keep upright. windmill his arms clockwise to keep upright. rotate one arm clockwise, the other counter-clockwise. curl up into a ball to keep from spinning.

windmill his arms clockwise to keep upright.

Two balls of putty of equal mass approach each other from opposite directions with equal speeds. They stick together and come to rest. Was momentum conserved in this collision?

yes

Suppose you have a very long straw that can reach from a cup of water on the ground level to the top of a very tall building. When you use a pump to suck on the straw in order to bring water up, you can bring the water up to any height with no problem. you can bring the water up to only a maximum height in the straw, when the pressure of the water column is approximately equal to the atmospheric pressure. you can bring the water up to only a certain height in the straw, because after it will flash freeze in the cup. you cannot bring the water up by more than a few inches.

you can bring the water up to only a maximum height in the straw, when the pressure of the water column is approximately equal to the atmospheric pressure.

A student sees the following question on an exam:A flywheel with mass 120 kg and radius 0.6 m, starting at rest, has an angular acceleration of 0.1 rad/s2. How many revolutions has the wheel undergone after 10 s?Which single formula might the student use to answerthe question?

θf = θi+ ωi(tf-ti)+ ½ α(tf-ti)2

A small wheel and a large wheel are connected by a belt. The small wheel is turned at a constant angular speed ωs. How does the angular speed of the large wheelωLcompare to that of the small wheel?

ωs>ωL