Physics Test
James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with a horizontal velocity of 25m/s. compare their times in the air. a. James reaches the surface of the lake first b. James and john reach the surface at the same time c. John reaches the surface first d. Cannot be determined
B. Same time
A 3m long plank of negligible mass has a 30kg mass at one end and a 40kg mass at the other. How far from the 30kg mass should the fulcrum be placed so that the plank is balanced? a. 1.5m b. 2.25m c. 1.71m d. 0.75m e. 1.29m
C
A 2kg mass is located at r = 2m i + 3m j and has velocity v = -4 m/s i - 1m/s j What is the angular momentum of the mass? a. -28 b. 10 c. 16 d. 20 e. 10
a. -28
A potential energy function is given by U(x) = (3N) x + (1N/m^2) x^3. What is the force that is associated with the potential energy function? a. -3N -(3N/m^2)x^2 b. (0.5N/m^2)x^2 + (1 N/m^2)x^4 c. (-0.5 N/m^2)x^2 + (-1 N/m^2)x^4 d. 3N + (1 N/m^2)x^2 e. -3N - (1 N/m^2)x^2
a. -3N -(3N/m^2)x^2
A rod has a length 2m at 20C. The length of the rod increases to 2.0005 m when the temperature increases to 40C. What is the coefficient of thermal expansion of the material from which the rod is made? a. 1.25E-5 b. 5E-5 c. 2.5E-5 d. 2E-5 e. 5E-5
a. 1.25E-5
A cars starts from rest and accelerates at 6m/s^2. How far does it travel in 3s? a. 27m b. 36m c. 18m d. 54m e. 9m
a. 27m
Determine the angle between the vectors A = 3i +1j and B = 2i +3j a. 37.9 b. 45.2 c. 30 d. 86 e. 52.1
a. 37.9
A projectile is launched from ground level at an angle of 40 above horizontal with a speed of 20m/s. If the projectile is moving over level ground, how far away from the launch position does it contact the ground? a. 40.2m b. 181m c. 54.2m d. 102m
a. 40.2m
Your bat hits the ball pitched to you with a 1500-N instant force. The ball hits the bat with an instant force whose magnitude is a. = to 1500 b. > than 1500 c. < than 1500 d. 0
a. = to 1500
If the net work done on an object is positive, then the object's kinetic energy a. Increases b. Remains the same c. Decreases d. 0 e. Not enough info
a. Increases
The slope of a tangent line at a given time value on a position versus time graph give a. Instantaneous velocity b. Instantaneous acceleration c. Average velocity d. Average acceleration e. Displacement
a. Instantaneous velocity
An external pressure applied to an enclosure fluid is transmitted unchanged to every point within the fluid" is known as a. Pascal's principle b. Archimedes' principle c. Fermat's principle d. Torricelli's law e. Bernoulli's principle
a. Pascal's principle
When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that a. The force of air resistance is equal to the weight of the parachutist b. The effect of gravity has died down c. The acceleration is equal to g d. The force of air resistance is equal to zero e. The effect of gravity increases as he becomes closer to the ground
a. The force of air resistance is equal to the weight of the parachutist
0.0001776 can also be written as a. 1.776E-3 b. 1.776E-4 c. 17.72E4 d. 1772E5 e. 177.2E7
b. 1.776E-4
How many significant figures are in 0.0067? a. 1 b. 2 c. 3 d. 4 e. 5
b. 2
)A rock is suspended from a scale reads 20N. A beaker of water is raised up so the rock is totally submerged in the water. The scale now reads 12.5N. What is the density of the rock? a. 1.6E3 b. 2.67E3 c. 2.5E3 d. 3E3 e. 2.33E3
b. 2.67E3
Internal human body temperature is often stated to be normal at 98.6F. What is that in Celsius? a. 145 b. 37 c. 22.8 d. 72.6 e. 120
b. 37
Identical forces act for the same length of time on 2 different masses. The change in momentum of the smaller mass is a. Smaller than the change in momentum of the larger, but not 0 b. = to the change in momentum of the larger one c. Larger than the change in the larger one d. 0 e. Not enough info
b. = to the change in momentum of the larger one
How a ship floats is described in terms of a. Torricelli's Equation b. Archimedes' principle c. Pascal's principle d. Bernoulli's principle e. Poiseuille's equation
b. Archimedes' principle
The metric prefix for one thousand is a. Milli b. Kilo c. Centi d. Giga e. Mega
b. Kilo
A person sits on a freely spinning lab stool. When this person extends her arms, a. Moment of inertia decreases and angular velocity increases b. Moment of inertia increases and angular velocity decreases c. Moment of inertia increases and angular velocity increases d. Moment of inertia decreases and angular velocity decreases e. Moment of inertia increases and angular velocity remains the same
b. Moment of inertia increases and angular velocity decreases
If a constant net torque is applied to an object, that object will a. Rotate with constant linear velocity b. Rotate with constant angular acceleration c. Rotate with constant angular velocity d. Having a decreased moment of inertia e. Having an increasing moment of inertia
b. Rotate with constant angular acceleration
As a car drives with its tires rolling freely without slippage, the type of friction acting between the tires and the road is a. Kinetic friction b. Static friction c. A combination of static and kinetic friction d. Neither static nor kinetic friction, but some other type of friction e. It is impossible to tell what type of friction acts in this situation
b. Static friction
A cone balanced on its small end is in a. Positive equilibrium b. Unstable equilibrium c. Negative equilibrium d. Neutral equilibrium e. Stable equilibrium
b. Unstable equilibrium
)It's more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, because a. us = uk b. uk < us c. Us < Uk d. Initially, the normal force is not perpendicular to the applied force e. The normal force is greater when the carton is at rest
b. uk < us
)Determine the scalar product of A = 4i + 4j - 2k and B = 3i -6j -3k. a. 42 b. 12i-24j+6k c. -6 d. 12i+24j+6k e. Undefined
c. -6
The velocity of an object as a function if time is given by v(t) = -3 -2t + t^2. Determine the Instantaneous acceleration at time t = 1s. a. -4 b. 3 c. 0 d. 2 e. -3
c. 0
Two air track carts move along an air track towards each other. Cart A has a mass of 450g and moves towards the right with a speed of 0.85 m/s and an air track cart B has a mass of 300g and moves toward the left with a speed of 1.12m/s. What is the total momentum of the system? a. 0.719 to the right b. 0.750 to the right c. 0.047 to the right d. 0.719 to the left e. 0.750 to the left
c. 0.047 to the right
A mass of 1000 kg hangs at the end of a steel rod 5m in length. The diameter of the rod is 0.8 cm and the Young's modulus for the rod is 210,000 MN/m^2. What is the elongation of the rod? a. 0.12cm b. 1.2cm c. 0.46cm d. 1.8cm e. 0.0047cm
c. 0.46cm
A car on a rollercoaster starts at zero speed at an elevation above the ground of 26m. It coasts down a slope, and then climbs a hill. The top of the hill is at an elevation of 16m. What is the speed of the car at the top of the hill? No friction. a. 18m/s b. 10m/s c. 14m/s d. 9m/s e. 6m/s
c. 14m/s
A uniform 2 kg circular disk of radius 20cm is rotating clockwise about an axis through its center with an angular speed 30 revolutions per second. A second 1.5kg uniform circular disk of radius 15 cm that is not rotating is dropped onto the first disk so that the axis of rotation of the first disk passes through the center of the second disk. What is the final angular speed of the two disk when they are rotating together? a. 12.7 rev/s b. 17.1 rev/s c. 21.1 rev/s d. 16.9 rev/s e. 19.2 rev/s
c. 21.1 rev/s
Vector A = 6m and 30 north of east. Vector B = 4m and 30 south of west. The resultant vector A + B is given by a. 10m at 60 E of N b. 10m at 60 N of E c. 2m at 30 N of E d. 10m at 30 N of E e. 2m at 60 N of E
c. 2m at 30 N of E
Vector A = -2i + 3j. Determine the magnitude and direction of vector A. a. 5, 56.3 b. -1,56.3 c. 3.61,124 d. 3.61,304 e. 3.61,56.3
c. 3.61,124
You ride on an elevator that is moving with a constant upward acceleration while standing on a scale. The scale will read a. = to your weight b. < than your weight c. > than your weight d. Could be either
c. > than your weight
Consider a flat steel plate with a hole through its center. When the plate's temperature is increased, the hole will a. Always contract b. Contract if it takes up less than half the plate's surface area c. Always expand d. Expand only if it takes up more than half the plate's surface area e. Remain the same size
c. Always expand
An object rests on an inclined surface. If the inclination of the surface is made steeper, what does the normal force on the object do? a. Increase b. The normal force is zero c. Decrease d. Stays the same e. Cannot be determined without additional info
c. Decrease
A liquid boils when its vapor pressure a. Exceeds the external pressure b. Is between the equilibrium vapor pressure and the external pressure c. Equals the external pressure d. Equals the equilibrium vapor pressure e. None of the above
c. Equals the external pressure
Because Earth's orbit is slightly elliptical, Earth actually gets closer to the sun during part of the year. When Earth is closer to the Sun its orbital speed is a. Less than when Earth is farther from the sun b. The same c. Greater than when Earth is farthest away from the sun
c. Greater than when Earth is farthest away from the sun
The total mechanical energy of the system a. Is not uniquely determined for most naturally occurring systems b. Is equally divided between kinetic and potential energy c. Is constant, if only conservative forces act d. Can never be negative e. Is either all kinetic or all potential energy
c. Is constant, if only conservative forces act
When an object experiences uniform circular motion, the direction of the acceleration is a. Is directed away from the center of the circular path b. In the same direction as the velocity vector c. Is directed toward the center of the circular path d. In the opposite direction of the velocity vector e. Depends on the speed of the object
c. Is directed toward the center of the circular path
The base SI unit of mass is a. Gram b. Milligram c. Kilogram d. Slug e. Megagram
c. Kilogram
For projectile motion, the horizontal component of a projectile's velocity a. Continuously increases b. Continuously decreases c. Remains a non-zero constant d. Is zero e. Any of the above, depending on position
c. Remains a non-zero constant
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height? a. The heavy object, has greater kinetic energy b. The heavy object, weighs more c. Same height d. The light object, smaller kinetic energy e. The light object, weighs less
c. Same height
2 children are riding on a merry go round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger angular displacement? a. Child A b. Child B c. Same non zero displacement d. 0 e. Not enough Info
c. Same non zero displacement
The average molecular kinetic energy of a gas can be determined by knowing only a. Volume b. Pressure c. Temperature d. # of molecules e. All of the above
c. Temperature
What does the word "normal" mean in the phrase "normal force"? a. The component of the force exerted by a surface parallel to the surface b. The force is due to contact c. The component of the force exerted by a surface perpendicular to the surface d. The force that is usually exerted by a surface
c. The component of the force exerted by a surface perpendicular to the surface
The three phases of matter can exist together in equilibrium at the a. Melting point b. Boiling point c. Triple point d. Critical point e. Evaporation point
c. Triple point
A stone is thrown straight up. When it reaches its highest point, a. Both velocity and acceleration = 0 b. More info c. V = 0 a is not 0 d. Neither are 0 e. V is not 0 a = 0
c. V = 0 a is not 0
Three masses are located in the x-y plane as follows: a mass of 6kg is located at (0m ,0m) a mass of 4kg is located at (3m, 0m) and a mass of 2kg is located at (0m ,3m). Where is the center of mass of the system? a. (1,1) b. (1,2) c. (2,1) d. (1,0.5) e. (0.5,1)
d. (1,0.5)
A spring with a spring constant of 2500N/m is stretched 4cm. What is the work required to stretch the spring? a. 0J b. 4J c. 3J d. 2J e. 1J
d. 2J
What is the vector product of A = -2i + 3j +1k and B = -1i -3j -2k? a. -5i + 2j -6k b. -4i + 3j -1k c. -9i - 3j -3k d. 2i - 9i - 2k e. -3i + 5j -9k
d. 2i - 9i - 2k
A golf club exerts an average force of 1000N on a 0.045kg golf ball which is initially at rest. The club is in contact with the ball for 1.8s. What is the speed of the ball as it leaves the tee? a. 35m/s b. 45m/s c. 30m/s d. 40m/s e. 50m/s
d. 40m/s
A man holding an 8 kg vacuum cleaner at arm's length, a distance of o.55 m from his shoulder. What is the torque on the shoulder joint if the arm is horizontal? a. 0.242Nm b. 0Nm c. 4.40Nm d. 48.2Nm e. 14.5Nm
d. 48.2Nm
A cyclist uses 500W of power while riding. How much force does her foot push with when she is traveling at 8m/s? a. 31N b. 4000N c. 80N d. 63N e. 160N
d. 63N
You are on an airplane traveling with a constant velocity at an altitude of 20,000m. What is the acceleration of gravity at that altitude? The radius of Earth is 6.38E6. a. 9.72 b. 9.69 c. 9.78 d. 9.75 e. 9.81
d. 9.75
Stress is a. The same as force b. The ratio of the change in length to the original length c. The strain per unit length d. Applied force per cross-section area. e. The ratio of elastic modulus to strain
d. Applied force per cross-section area.
List the 4 fundamental forces in nature. a. Gravitation, Normal, Kinetic friction, static friction b. Gravitation, contact, strong nuclear, weak nuclear c. Gravitation, electromagnetic, contact, nuclear d. Gravitation, electromagnetic, strong nuclear, weak nuclear e. Gravitation, normal, tension, friction
d. Gravitation, electromagnetic, strong nuclear, weak nuclear
You are trying to cross a river that flows due south with a strong current. You start out in your motorboat on the west bank desiring to reach the east bank directly east from your starting point. You should head your boat a. North b. South c. East d. NE e. SE
d. NE
Suppose that an object is moving with a constant velocity. Make a statement concerning its acceleration. a. The acceleration must be constantly decreasing b. The acceleration must be constantly increasing c. The acceleration must be a constant non-zero value d. The acceleration must be equal to zero e. A statement cannot be made without additional value
d. The acceleration must be equal to zero
Angular momentum cannot be conserved if a. The angular velocity changes b. There is a net force on the system c. The moment of inertia changes d. The net torque is not zero e. The angular acceleration changes
d. The net torque is not zero
Is it possible for a system to have negative potential energy? a. No, that has no meaning b. Yes, as long as kinetic energy is + c. No, K = P d. Yes, potential energy is relative e. Yes, as long as the total energy is positive
d. Yes, potential energy is relative
What is the absolute pressure at a distance 7m below the surface of the lake? Assume the density of the water in the lake is 1000kg/m^3. a. 1.07E5 b. 7E3 c. 0.69E5 d. 4.66E5 e. 1.70E5
e. 1.70E5
An elastic collision of two objects is characterized by the following a. Total energy remains constant b. Total momentum is conserved c. Total kinetic energy remains the same d. A & B e. A,B, & C
e. A,B, & C
Bernoulli's principle is a statement of the conservation of a. Angular momentum b. Linear momentum c. Kinetic energy d. Mass e. Energy
e. Energy
At a fixed depth within a fluid at rest, the pressure pushing upward is a. Zero, because pressure only pushes equal in all horizontal directions b. Less than the pressure pushing downward c. Zero, because the fluid above does not support the weight of the fluid below d. Greater than the pressure pushing upward e. Equal to the pressure pushing upward
e. Equal to the pressure pushing upward
A car of mass m goes around a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to a. Mg b. Mg/2 c. Mgsinx d. Tan[(v^2)/(rg)] e. M(v^2)/r
e. M(v^2)/r
In the absence of an external force, a moving object will a. Move with constant velocity in a circular orbit b. Gradually speed up until it reaches its terminal velocity c. Slow down and eventually comes to a stop d. Stop immediately e. Move with constant velocity in the straight line
e. Move with constant velocity in the straight line
Two systems are in thermal equilibrium. The two systems are at the same a. Pressure and temperature b. Pressure c. Height d. Volume e. Temperature
e. Temperature
An object of mass m sits on a flat table. The earth pulls on this object with force mg, which we will call the action force. What is the reaction force? a. The object pushing down on the table b. The table pulling up on the earth c. The table pushing up on the object d. The table pushing down on the floor e. The object pulling up on the earth
e. The object pulling up on the earth
Several forces act on an object at rest. It is known that the sum of the forces acting on the object is zero. Which statement is necessarily true? a. The object's center of mass may accelerate and the object may begin to rotate b. The object will remain stationary c. The object's center of mass may move in such a way that the object will roll without slipping d. The object's center of mass may accelerate, but the object will remain in the same orientation e. The object's center of mass will not move, but the object may begin to rotate
e. The object's center of mass will not move, but the object may begin to rotate