This is Sum Physics stuff you should use to get GigaBrain In physics
What is the work required by friction to stop a 23.7 kg block sliding on a table if it initially has a speed of 15.0 m/s? a) - 178 J b) - 3480 J c) - 356 J d) - 5330 J e) -2670 J
e) -2670 J
A 2.0-kg laptop is carried with constant velocity over a distance of 30.0 m. What is the net work done on the laptop? a) 547.9 J b) 1029J c) -45.6 J d) 19.6 J e) 0 J
e) 0 J
A (vertical) spring pendulum is pulled down from the equilibrium position by 0.04 m and then let go. You observer the pendulum oscillate (ignore friction so you don't have to worry about damping). If the mass is 0.1 kg and the spring constant is 2.0 N/m, how long will it take the pendulum to move through the equilibrium point for the first time? a) 0.21 s b) 5.3 s c) 0.04 s d) 1.4 s e) 0.35 s
e) 0.35 s
What is the period of a disk rotating at 40 rpm? a) 0 s b) 2 s c) 1 s d) 0.5 s e) 1.5 s
e) 1.5 s
A grinding wheel running at 6000 rpm. When it is unplugged it takes 6.3 seconds for the wheel to stop. What is the magnitude of the angular acceleration during this process? a) 12 rad/s^2 b) 630 rad/s^2 c) 91.9 rad/s^2 d) 0.5 rad/s^2 e) 100 rad/s^2
e) 100 rad/s^2
The cable of a construction crane has a maximum strength of 12000 N. When lifting a 500 kg crate what maximum upward acceleration can the cable sustain without breaking? (magnitude only) a) 3.7 m/s^2 b) 24.0 m/s^2 c) 9.8 m/s^2 d) 0.8 m/s^2 e) 14.2 m/s^2
e) 14.2 m/s^2
A 50.0 kg person is standing at the tip of a diving board. The board itself is a uniform, 4 m long piece of wood with a mass of 25.0 kg. Find the magnitude of the force F1 exerted by the first support to hold down the diving board. Hint: think about the best location for the axis of rotation and then use the torque equation. 1 m between the two supports. The first support is right at the left end. 3 m between second support and where the diver is standing. a) 2189 N b) 490 N c) 12 N d) 25 N e) 1715 N
e) 1715 N
A uniform 2.3-kg disk with radius 0.18 m is rolling (without slipping) over a horizontal surface at a speed of 3.5 m/s. What is the total kinetic energy of the disk? [Ignore friction] a) 14 J b) 28 J c) 1.4 J d) 9.8 J e) 21 J
e) 21 J
A ball has a kinetic energy of 65.1 J and is moving with a velocity of 5.3 m/s. What is the mass of the ball? a) 5.1 kg b) 0.7 kg c) 1.2 kg d) 2.3 kg e) 4.6 kg
e) 4.6 kg
A 1.4 kg glob of clay is thrown horizontally with a speed of 3.4 m/s at a 0.5 kg block that is initially at rest. The block is standing on a frictionless surface. Assuming the clay sticks to the block, what is the kinetic energy of the system after the collision? a) 1.3 J b) 7.8 J c) 9.5 J d) 11 J e) 6.0 J
e) 6.0 J
A UPS van drives 32.5 km north. Then it turns west and drives 9.0 km. Finally, the van drives19.4 km south. The entire trip takes 40 minutes. What is the average velocity of the truck?(Remember the difference between average speed and average velocity!) a) 13.5 m/s b) 21.2 m/s c) 9.2 m/s d) 2.7 m/s e) 6.6 m/s
e) 6.6 m/s
When a ceiling fan rotating with an angular velocity of 3.60 rad/s is turned off, a frictional torque of 0.240 Nm slows it to a stop in 45 s. What is the moment of inertia of the fan? a) 3 kgm^2 b) 2 kgm^2 c) 4 kgm^2 d) 1kgm^2 e) 5 kgm^2
a) 3 kgm^2
In an elastic collision, object A of mass 1.5 kg and moving at 2.5 m/s to the left collides with an identical 1.5 kg object B initially at rest. What is the velocity of object A after the collision? Ignore friction. a) 0 m/s b) 5 m/s to the left c) 5 m/s to the right d) 2.5 m/s to the left e) 2.5 m/s to the right
a) 0 m/s
A 4.5 kg block starts from rest at the top of a 1.3 m frictionless ramp. After reaching the horizontal portion it encounters a spring with k = 7.6 x 10^3 N/m. Determine the maximum length the spring gets compressed. a) 0.12 m b) 0.015 m c) 0.039 m d) 0.44 m e) 0.061 m
a) 0.12 m
Three balls are placed on a meter stick. Ball 1, at the 0-cm mark, has a mass of 3.0 kg. Ball 2, at the 80-cm mark, has a mass of 2.0 kg. Ball 3, at the 90-cm mark, has a mass of 1.0 kg. The mass of the meter stick is negligible. Where is the center of mass of this system? (find the x coordinate of the center of mass using the 0-mark of the meter stick as the origin of your coordinate system) a) 0.42 m b) 0.65 m c) 0.26 m d) 0.91 m e) 0.05 m
a) 0.42 m
A marble rolling over a horizontal table has a velocity of 1.4 m/s as it reaches the edge of the table and falls down to the floor. The marble lands 0.6 m from the edge (horizontal distance). How high is the table? a) 0.9 m b) 1.6 m c) 1.4 m d) 1.2 m e) 1.0 m
a) 0.9 m
A disk spins at 15 rpm (revolutions per minute). The disk has a radius of 0.45 m. What is the angular velocity of the disk? a) 1.6 1/s b) 94.2 1/s c) 6.75 1/s d) 19.4 1/s e) 0.5 1/s
a) 1.6 1/s
If a car travels 100 kilometers using 8.5 liters of gasoline, how many miles can it travel on a single gallon of gasoline? 1 gallon = 3.785 liters; 1 mile = 1.609 km; a) 28 miles b) 28 miles c) 140 miles d) 7.3 miles e) 37 miles
a) 28 miles
A 2.5 kg mass falls vertically down from a bridge 41.9 m high. The initial velocity is 0. What is the magnitude of the momentum of the object after 1.4 seconds? a) 34.3 kgm/s b) 13.7 kgm/s c) 0 d) 1.6 kgm/s e) 9.8 kgm/s
a) 34.3 kgm/s
A grindstone, initially at rest, is given a constant angular acceleration so that it makes 5.20 rev in the first 3.70 s. What is its angular acceleration? a) 4.77 rad/s^2 b) 17.7 rad/s^2 c) 1.41 rad/s^2 d) 2.39 rad/s^2 e) 0.760 rad/s^2
a) 4.77 rad/s^2
A baseball is thrown with an initial velocity of 12.0 m/s at an angle of 60 degree with respect to the level ground. What is the horizontal velocity of the ball at 1.0 seconds after it was kicked? (ignore air resistance) a) 6.0 m/s b) 10.0 m/s c) 4.0 m/s d) 12.0 m/s e) 8.0 m/s
a) 6.0 m/s
A soccer ball (m = 0.59 kg) moving horizontally to the right hits a wall with a speed of 11.5 m/s. After the collision the ball bounces back and moves horizontally to the left at a speed of 10.4 m/s. If the collision lasts for 0.02 s, what is the magnitude of the (average) force exerted on the ball by the wall? a) 646 N b) 156.2 N c) 32.5 N d) 339.3 N e) 65.9 N
a) 646 N
A soap box cart accelerates down a hill with an acceleration of 2.5 m/s^2. It covers the 115 m long track in 7.2 seconds. What was the cart's initial velocity? a) 7.0 m/s b) 50.2 m/s c) 2.5 m/s d) 18.7 m/s e) 12.1 m/s
a) 7.0 m/s
A 12.0 kg box is pulled along a horizontal surface by a force F of 38.0 N applied at an angle of 62 degrees with respect to the surface as shown in the drawing. Find the magnitude of the normal force exerted by the surface onto the box. a) 84.0 N b) 338.0 N c) 515.9 N d) 99.7N e) 141.8 N
a) 84.0 N
You want to paddle a boat straight across the Mississippi River. You are able to paddle the boat with a speed of 2.2 m/s relative to the water, and the current flows at a speed of 1.1 m/s. In what direction (angle), relative to the river bank, do you need to point the boat to cross the river in the shortest time? The width of the river is 95.0 m. a) 90 degrees b) 80 degrees c) 70 degrees d) 60 degrees e) 50 degrees
a) 90 degrees
A bullet is fired into a block of wax and gets embedded in it. The block sits on a frictionless surface. Which of the following statements correctly describes this process? a) Momentum is conserved. Kinetic energy is not conserved. b) Momentum is conserved. Kinetic energy is conserved c) Momentum is not conserved. Kinetic energy is not conserved. d) Momentum is not conserved. Kinetic energy is not conserved.
a) Momentum is conserved. Kinetic energy is not conserved.
An object moving due south while accelerating with 3 m/s2. What is the direction of the net force acting on this object? a) South b) North c) West d) East
a) South
A train consisting of the engine and 5 cars is moving at constant velocity. Rank the tension forces between the cars and between the first car and the engine. Which of these tension forces has the largest magnitude? (end) 3000kg (5), 3000kg (4), 3000kg (3), 3000kg (2), 3000kg (1), 5000kg (engine) (front) a) Tension between car 1 and the engine. b) Tension between cars 3 and 2 c) Tension between cars 5 and 4 d) Tension between cars 2 and 1 e) Tension between cars 4 and 3
a) Tension between car 1 and the engine.
When we discussed Bernoulli's equation in class we saw that it is closely related to another important principle in physics. Which of the following options is the correct way to complete this sentence: Bernoulli's equation is an expression of ... a) conservation of energy b) conservation of mass c) conservation of electric charge d) conservation of linear momentum e) conservation of angular momentum
a) conservation of energy
The motion of a spring pendulum starts with initial conditions x = 0 at t = 0. Which of the answers is the correct equation for x(t), the position of the pendulum as function of time? Assume the amplitude of the oscillation is A. a) x(t) = A sin(√(k/m)t) b) x(t) = A sin(√(g/m)t) c) x(t) = A cos(√(k/m)t) d) x(t) = A +sin(√(k/M)t)-cos(√(k/m)t) e) x(t) = A cos(t/k)
a) x(t) = A sin(√(k/m)t)
A soft ball (m = 0.17 kg) moving horizontally to the right hits a wall with a speed of 16.2 m/s. After the collision the ball bounces back and moves horizontally to the left at a speed of 13.8 m/s. If the collision lasts for 0.0015 s, what is the magnitude of the (average) force exerted on the ball by the wall? a) 2700 N b) 3400 N c) 270 N d) 340 N e) Zero N
b) 3400 N
Find the center of mass of the Earth - Moon system. Express your answer as the distance between the center of the Earth and the center of mass of the Earth - Moon system. mEarth= 5.97x10^24 kg mMoon= 7.36x10^22 kg Distance between Earth and Moon= 3.84x10^8m a) 3.79 x 10^6 m b) 4.68 x 10^6 m c) 1.92 x 10^8 m d) 3.79 x 10^8 m e) 4.68 x 10^8 m
b) 4.68 x 10^6 m
A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 280 m/s and 370 m/s, respectively. Determine the initial magnitude of the velocity of the projectile and the angle with respect to the horizontal at which it is fired. a) 460 m/s, 37 degree b) 460 m/s, 53 degree c) 650 m/s, 26 degree d) 330 m/s, 37 degree e) 650 m/s, 53 degree
b) 460 m/s, 53 degree
Two students, Dan and Jesse, are talking about their upcoming Physics MidTerm-1 exam while maintaining a social distance of 6 feet between them. Dan's mass is 68 kg, and Jesse's mass is 71 kg (their masses include their masks also!). Determine the gravitational attraction force between them. 1 meter = 3.28 feet. a) 0 N b) 9.6 x 10^-8 N c) 8.9 x 10^-9 N d) 1.8 x 10^-7 N e) 1.1 x 10^-6 N
b) 9.6 x 10^-8 N
An apple falls from a tree straight down. It reached ground after 0.6 seconds. Find the original height of the apple in the tree (above ground) (Hint: the initial velocity of the apple is 0) a) 0.6 m b) 1.8 m c) 3.1 m d) 2.9 m e) 4.8 m
b) 1.8 m
A small crane equipped with a 2550-W motor lifts a 220.0-kg crate 15.0 m from ground level to a work platform. Assuming the motor runs at full power, how long will it take until the crate arrives at the platform? a) 13.7 s b) 12.7 s c) 11.7 s d) 14.7 s e) 15.7 s
b) 12.7 s
Here is a problem about echos and the speed of sound. A person standing somewhere between two vertical cliffs shouted "Yahoo". She heard the 1st echo after 2 seconds and the second echo 6 seconds after the shout. If the speed of sound is 330 m/s, what is the distance between the cliffs? a) 514 m b) 1320 m c) 5100 m d) 1950 m e) 2540 m
b) 1320 m
Jane, looking for Tarzan is running at top speed (6.25 m/s) and grabs a vine hanging vertically from a tall tree in the jungle. How high can she swing upward (measured relative to her height when she grabs the vine) a) 3.0 m b) 2.0 m c) 2.5 m d) 3.5 m e) 4.0 m
b) 2.0 m
A potter's wheel is a uniform disk of mass 4.50 kg and radius 0.650 m and can spin freely around a vertical axis through its center. With the wheel spinning at an angular speed of 4.70 rad/s, a small piece of clay of mass 0.870 kg is dropped at the outer edge of the wheel and sticks to it. Find the final angular speed of the wheel+clay. Treat the piece of clay as a point particle.f a) 4.70 rad/s b) 3.39 rad/s c) 2.95 rad/s d) 2.35 rad/s e) 3.94 rad/s
b) 3.39 rad/s
A string of length 0.5 m is fixed at both ends. The string is plucked and a standing wave is set up that is vibrating at the string's fundamental mode (1st harmonic). The wave velocity is 300 m/s. What is the frequency of this wave? a) 100 Hz b) 300 Hz c) 150 Hz d) 200 Hz e) 250 Hz
b) 300 Hz
Which of the following statements about a spring pendulum is correct? a) Changing the spring constant while keeping the mass constant does not change the period of the pendulum. b) If you double the mass and double the spring constant, the frequency of the pendulum does not change. c) If the pendulum oscillates with a small amplitude it has a smaller period compared to the same pendulum oscillating with a large amplitude. d) The frequency of the pendulum decreases if you replace the spring with a spring that's twice as long but has the same spring constant. e) The frequency of the pendulum changes when you bring it to the Moon
b) If you double the mass and double the spring constant, the frequency of the pendulum does not change.
Only one constant force of 30 N acts on an object of constant mass m. Which of the following statements is correct? a) The acceleration has to be 0 at all times. b) The acceleration is not zero but is constant. c) The velocity of the object is is not zero but it is constant. d) The net force on the object is 0. e) The velocity has to be 0 at all times.
b) The acceleration is not zero but is constant.
A small cart is rolling at constant velocity on a flat track. It fires a ball straight up into the air as it moves. After it is fired, what happens to the ball and in particular, where will it land with respect to the cart? a) The ball will land ahead of the cart b)The ball will land on the cart c) The ball will land behind the cart
b) The ball will land on the cart
What is the weight of the water in a pool of dimensions 25 m x 6 m x 1 m. Assume the pool is completely filled. The density of water is 1000 kg/m^3 a) 2.7 E5 N b) 7.2 E4 N c) 1.5 E6 N d) 1.5 E5 N e) 7.2 E6 N
c) 1.5 E6 N
A 10.0 kg box is pulled along a horizontal surface by a force F of 50.0 N applied at a 25o angle with respect to the surface as shown in the drawing. A kinetic friction force of 28.5 N acts on the box while it's moving. Find the acceleration of the box. a) 3.4 m/s^2 b) 1.3 m/s^2 c) 1.7 m/s^2 d) 4 m/s^2 e) 0.2 m/s^2
c) 1.7 m/s^2
A 130.0-kg astronaut pushes on a spacecraft with a force of 250 N in "gravity-free" space. The spacecraft has a total mass of 9.0 x 10^3 kg. Determine the magnitude of the acceleration of the astronaut during the pushing. a) 36 m/s^2 b) 0.028 m/s^2 c) 1.9 m/s^2 d) 0.52 m/s^2 e) 0 m/s^2
c) 1.9 m/s^2
A bicycle has wheels that are 60 cm in diameter. What is the angular speed of these wheels when it is moving at 4.0 m/s? a) 1.2 rad/s b) 0.36 rad/s c) 13 rad/s d) 7.6 rad/s e) 4.8 rad/s
c) 13 rad/s
A student accidentally drops her physics book from the edge of a ninth floor balcony while she was reading the sections that would be discussed in the next lecture class. In two seconds how far will it fall (ignore air resistance)? a) 9.8 m b) 39.2 m c) 19.6 m d) Not sufficient information to calculate the answer. e) 4.9 m
c) 19.6 m
A box weighing 56.0 N rests on a table. A rope tied to the box runs vertically upward over a pulley and a weight is hung from the other end as shown in the drawing. Determine the magnitude of the normal force that the table exerts on the box if the weight hanging on the other side of the pulley weighs 36.0 N. (assume that both the rope and the pulley are massless) a) 10 N b) 15 N c) 20 N d) 25 N e) 30 N
c) 20 N
A toy rocket is launched from level ground with an initial velocity of 10.1 m straight up. What is the maximum height above ground the rocket reaches? (ignore air resistance; acceleration due to gravity is 9.8 m/s^2, down) a) 9.8 m b) 0.51 m c) 5.2 m d) 10.2 m e) 1.0 m
c) 5.2 m
The coefficient of kinetic friction between the tires of a car and a horizontal road surface is 0.52. If the car is traveling at an initial speed of 25 m/s, and then slams on the breaks so the car skids straight ahead to a stop, how far does the car skid? Assume the mass of the car to be 1000 kg. a) 57 m b) 16 m c) 61 m d) 32 m e) 123 m
c) 61 m
A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 280 m/s and 370 m/s, respectively. Determine how long the projectile is in the air if the initial height and the final height are the same. a) 45 s b) 38 s c) 76 s d) 19 s e) 10 s
c) 76 s
Two identical cups are filled to the same level with water. One of the two cups has ice cubes floating in it. Which weighs more? a) Ice cubes do not float in water so this question cannot be answered b) The cup with the ice cubes c) Both cups weigh the same d) The cup without the ice cubes
c) Both cups weigh the same
Which of the following quantities is not a vector? a) Angular Momentum b) Velocity c) Density d) Force e) Acceleration
c) Density
How is the smoke drawn up a chimney affected when a wind is blowing outside across the top of the chimney? What is the most likely answer based on what we have discussed in the last few lectures? a) The smoke rises more slowly in the chimney b) The smoke is forced back down the chimney c) The smoke rises more rapidly in the chimney d) The smoke is unaffected
c) The smoke rises more rapidly in the chimney
A large truck collides head-on with a small compact car. During the collision: a) The truck exerts a greater amount of force on the car than the car exerts on the truck. b) The truck exerts a force on the car but the car does not exert a force on the truck. c) The truck exerts the same amount of force on the car as the car exerts on the truck. d) The car exerts a greater amount of force on the truck than the truck exerts on the car.
c) The truck exerts the same amount of force on the car as the car exerts on the truck.
What is the direction of the angular momentum vector of the spinning disk spinning counterclockwise? a) radially inward in the plane of the disk b) along the axis, down c) along the axis, up d) radially outward in the plane of the disk e) tangential to the disk
c) along the axis, up
Two skaters start from rest and push off of each other on ice where the friction is negligible. One is a 64.0 kg woman and one is a 93.0 kg man. The woman moves away with a velocity of +2.83 m/s. Find the velocity of the man. a) -4.11m/s b) -2.83 m/s c) -1.02 m/s d) -1.95 m/s e) 0 m/s
d) -1.95 m/s
An oval shaped Nascar track is 1600 m long. A drive completes a lap in 40 s. What is his average velocity for that lap? a) .4 m/s b) 14 m/s c) 40 m/s d) 0 m/s e) 400 m/s
d) 0 m/s
What length is required for a simple pendulum to oscillate with a frequency of 1 Hz on the surface of the Moon. (gMoon = 1.6 m/s^2) a) 0.25 m b) 1.0 m c) 0.33 m d) 0.04 m e) 1.1 m
d) 0.04 m
A rope holds a 25-kg rock at rest on a frictionless inclined plane. The angle of the incline is 30 degree with respect to the horizontal plane. Determine the magnitude of tension in the rope. a) 210 N b) 250 N c) 150 N d) 120 N e) 180 N
d) 120 N
A 1.5 m^3 object made of an unknown material if placed into a large water tank (the density of water is 1000 kg/m^3). You observe that the object is fully immersed in the water and stays at a constant position 2.5 m below the surface (meaning it's not moving up or sinking). What is the mass of this object? a) 750 kg b) 1000 kg c) 2000 kg d) 1500 kg e) 500 kg
d) 1500 kg
A 325-N force accelerates a 50.0-kg crate from rest along a horizontal frictionless surface for a distance of 20.0 m. What is the final speed of the crate? a) 32.2 m/s b) 259 m/s c) 11.4 m/s d) 16.1 m/s e) 131 m/s
d) 16.1 m/s
Convert 3500 meter to miles (1 mi = 1600 m) a) 7.9 mi b) 0.46 mi c) 12.8 mi d) 2.2 mi e) 1900 mi
d) 2.2 mi
A 4.6 kg block sits on a 28o The block is not moving. What is the static friction force acting on the block? a) 19.8 N b) 14.8 N c) 0.5 N d) 21.2 N e) 8.3 N
d) 21.2 N
A rectangular barge is floating on a river (dimensions of the barge: width 5m, length 10m, height 2m). When empty, 0.25m of the barge is submerged in the water. That increased to 0.75m when a load is added. Determine the mass of the load. The density of water is 1000 kg/m^3. a) 2000 kg b) 500 kg c) 10000 kg d) 25000 kg e) 5000 kg
d) 25000 kg
Water flows through a horizontal pipe at 4 m/s. At the end of the pipe is a nozzle open to air with smaller radius and the water comes out with a velocity of 25 m/s. Since it's exposed to air, the pressure at the nozzle is equal to the air pressure so use P2 = 10^5 Pa. What is the pressure inside the pipe? The density of water is 1000 kg/m3. a) 100000 Pa b) 0.5 Pa c) 217000 Pa d) 404500 Pa e) 15400 Pa
d) 404500 Pa
Vector A has a magnitude A= 5 m and makes an angle of 30 degrees with respect to the x-axis. Vector B has components Bx=3 m and By = 4 m. Add these two vectors, C = A+B, and determine the direction of the resultant vector C, ie the angle C forms with the x-axis. a) 12.9 degrees b) 30 degrees c) 0.26 degrees d) 41.6 degrees e) 48.3 degrees
d) 41.6 degrees
A 1.3 kg ball is whirled on the end of a string in a horizontal circle of radius 2.0 m at a constant speed of 8.0 m/s. What is the tension force in the string? a) 0.65 N b) 5.2 N c) 21 N d) 42 N e) 98 N
d) 42 N
You watch an 81.0 kg man sliding down a water slide. He starts at a height of 5.0 m above the pool. What is his speed as he hits the water? a) 39 m/s b) 98 m/s c) 11 m/s d) 9.9 m/s e) 17 m/s
d) 9.9 m/s
In lecture I used a red plastic ball when discussion uniformly accelerated motion. I tossed the ball straight up and then caught it at the same height as it came down. Which of the following statements correctly describes the motion of the ball as it flies up and down. (ignore air resistance) a) The velocity of the ball has its largest value at the highest point of the ball's path. b) The velocity of the ball is constant. c) The acceleration due to gravity changes direction at the highest point of the ball's path. d) As the ball flies up and down the acceleration due to gravity is constants.
d) As the ball flies up and down the acceleration due to gravity is constants.
Why does the stream of water from a faucet become narrower as it falls? a) The air pressure decreases as the water falls b) This is an application of Archimedes' Principle c) The water cools down and the molecules move closer together d) As the velocity of the water increases the cross section decreases because of the continuity equation e) As the velocity of the water increases the cross section increases because of the continuity equation
d) As the velocity of the water increases the cross section decreases because of the continuity equation
When we started to talk about free fall in lecture, I showed you two objects - a physics book and a letter-sized piece of paper that I dropped from equal height. Without air resistance, which of the following statements is correct? a) The outcome of the experiment depends on the initial height of the objects. b) The acceleration due to gravity of the falling book is different than the acceleration due to gravity of the falling sheet of paper. c) The heavier book will reach ground first. d) Both objects reach ground at the same time. e) The lighter sheet of paper will reach the ground first.
d) Both objects reach ground at the same time.
In an experiment you observe 3 objects accelerate at the same rate and in the same direction. The acceleration is 4 m/s^2 and is constant. Object A has a mass mA=3kg, object B's mass is mB=2kg and object C's mass is mC=1kg. Which of the following statements about the magnitudes of the net forces acting on these objects is correct? a) constant acceleration so FNet_A = 0, FNet_B = 0 and FNet_C = 0 b) FNet_C = FNet_B and FNet_A = 0 c) FNet_A < FNet_B < FNet_C d) FNet_A > FNet_B > FNet_C e) FNet_A = FNet_B = FNet_C (the forces are equal but NOT 0)
d) FNet_A > FNet_B > FNet_C
What do you have to do to double the frequency f of a simple pendulum? a) Make the length half as long b) Reduce the mass of the pendulum by a factor of 4 c) Move the pendulum to the moon d) Make the length 4 times shorter e) Double the mass of the pendulum
d) Make the length 4 times shorter
In lecture we watched a video clip of a figure skater. When spinning, she brought her arms closer to her body. Looking at this from a physics perspective, what happened? a) She decreased her angular momentum b) Her weight changed c) She increased her moment of inertia d) She reduced her moment of inertia e) She increased her angular momentum
d) She reduced her moment of inertia
The distance between two points on a wave that are in the same state of motion is called: a) Amplitude b) Wave velocity c) Frequency d) Wavelength e) Period
d) Wavelength
A soccer is kicked on a level field. You observe the ball following its parabolic path until it lands back on the field. Where along its path has the ball the smallest velocity (magnitude of the velocity vector - and no, the answer is not after it landed. We only look at the ball while it's still flying; ignore air resistance) a) The magnitude of the velocity of the ball is constant for projectile motion. b) As it comes down when its height is half the maximum height. c) Right after the kick when the ball takes off. d) As it goes up when it reaches half of the maximum height above ground. e) At the highest point of its path.
e) At the highest point of its path.
A football quarterback throws a forward pass on the run at a 38 degree angle and then keeps running without changing his velocity. Can he throw the pass and then catch it himself? Which of the options give the correct answer and the correct reasoning? a) No, because the quarterback runs in a straight line and the football follows a parabola b) Yes, because the quarterback and the ball have the same initial velocity c) Yes, because the acceleration due to gravity is constant and directed downward d) Yes, even though the ball has a larger initial velocity it also has to cover a much longer distance along its parabolic path. e) No, because the initial horizontal velocity of the ball and and the initial horizontal velocity of the quarterback are different and during projectile motion the horizontal velocity component remains constant
e) No, because the initial horizontal velocity of the ball and and the initial horizontal velocity of the quarterback are different and during projectile motion the horizontal velocity component remains constant
A 65.0 kg student stands on a bathroom scale in an elevator cabin. The scale reads 561 N. (I know that all our bathroom scales are calibrated in lbs but do you really want to do the extra unit conversion?). What does this information tell you about the state of motion of the elevator cabin? a) There is no elevator cabin that can hold a 65 kg student b) The elevator cabin is accelerating up c) The elevator cabin is in free fall d) The elevator cabin is at rest or moving with constant velocity e) The elevator cabin is accelerating down
e) The elevator cabin is accelerating down
At the Tour de France a cyclist is going up a hill. He is moving with constant velocity. Wx and Wy are the components of the weight force parallel to the surface (Wx) and perpendicular to the surface (Wy). Fapplied is the force of the cyclist (peddling) and Ffriction is the kinetic friction force. Which of the following statements is not correct? a) While the cyclist is moving, the applied force Fapplied must be larger than the magnitude of Wx b) While the cyclist is moving, the magnitude of the kinetic friction force is independent of the velocity of the cyclist. c) The net force FNet_x in the x direction (parallel to the surface) is 0 d) While the cyclist is moving, the applied force Fapplied must be larger than the magnitude of the friction force. e) The magnitude of the normal force is larger than the magnitude of the weight W.
e) The magnitude of the normal force is larger than the magnitude of the weight W.
Two vectors G and F are are given such that their sum is 0: G+F=0 Which of the following statements about the magnitudes and directions of the vectors is correct? a) The vectors have different magnitude but the same direction b) Both vectors must have magnitude 0 c) The vectors have different magnitudes and opposite direction d) The vectors have the same magnitude, same direction e) The vectors have the same magnitude, opposite direction
e) The vectors have the same magnitude, opposite direction
Complete the following statement: Momentum will be conserved in an isolated two-body collision only if a) the kinetic energy of the system is conserved. b) the collision is perfectly elastic. c) both bodies come to rest. d) the collision is completely inelastic. e) the net external force acting on the two-body system is zero.
e) the net external force acting on the two-body system is zero.
A toy rocket is launched with an initial velocity of 18.5 m/s at an angle of 65 degrees with respect to a level field. What are the horizontal (x) and vertical (y) components of the initial velocity? a) vox = 16.8 m/s, voy = 7.8 m/s b) vox = 12.8 m/s, voy = 12.8 m/s c) vox = 18.5 m/s, voy = 0 m/s d) vox = 0 m/s, voy = 18.5 m/s e) vox = 7.8 m/s, voy = 16.8 m/s
e) vox = 7.8 m/s, voy = 16.8 m/s
