Physics Final

which of the equations are dimensionally consistent? v^2=2ax

Consistent

which of the equations are dimensionally consistent? x=vt

Consistent

Rank the vectors in the above diagram in order of increasing magnitude. A ----> B / C <---- D \

1:A 2:B 3:D 4:C

Jogger A has a mass m and a speed v, jogger B has a mass m/3 and a speed 2v, jogger C has a mass 2m and a speed v/3, and jogger D has a mass 9m and a speed v/3. Rank the joggers in order of increasing kinetic energy. Indicate ties where appropriate.

1:C 2:A 2:D 4:B

Rank the vectors in the above diagram in order of increasing value of their x components. A ----> B / C <---- D \

1:C 2:B 3:A 4:D

Rank the vectors in the above diagram in order of increasing value of their y components. A ----> B / C <---- D \

1:D 2:C 3:A 4:B

Rank the following values in order of increasing number of significant digits. 6.2x10^3 1.0375x10^9 300 300. 40,000.0

2: 6.2x10^3 4: 1.0375x10^9 1: 300 3: 300. 5: 40,000.0

Stones are thrown horizontally, with the same initial velocity, from the tops of two different buildings, A and B. The stone from building A lands 6 times as far from the base of the building as does the stone from building B. What is the ratio of building A's height to building B's height? 36 None of these choices. 1/36 6 1/6 sqr6

36

A certain amount of work W is required to accelerate a motorcycle from rest to a speed v. How much work is required to accelerate the same motorcycle from v/3 up to a speed v? W/3 W/4 W/10 8W/9 W/9

8W/9

If the airplane had double the acceleration and double the necessary takeoff speed, how long would the runway have to be? Double the length Half the length Four times the length Same length

Double the length

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. M1 g is ... T1.

Equal to

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. T2 is ... T1.

Equal to

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. T4 is ... M3 g.

Equal to

The truck is coasting along with a constant velocity on a horizontal surface, neglecting friction. FT>FC FT<FC FT=FC>0 FT=FC=0

FT=FC=0

A truck is pulling a car. FT is the magnitude of the force that the truck exerts on the car FC is the magnitude of the force that the car exerts on the truck. Consider the following scenarios independently.The truck is slowing down on a horizontal surface. FT>FC FT<FC FT=FC>0 FT=FC=0

FT=FC>0

The truck is driving up a mountain with a constant velocity, neglecting friction. FT>FC FT<FC FT=FC>0 FT=FC=0

FT=FC>0

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The average acceleration is zero.

False

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The average speed is zero.

False

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The initial velocity and final velocity are equal

False

A cart of mass m can move without friction on an airtrack. Initially, it is at rest. Then, for a limited time t , it is pushed down the track with a constant force F. Which of the following statements are true. You exert a larger force on the cart than the cart exerts on you.

False

Choose whether each of the following statements is true or false. An object that is accelerating must have a nonzero average velocity.

False

Choose whether each of the following statements is true or false. In order to move a massive crate sitting on the floor, the force you apply to the crate has to overcome the force of the crate pushing back on you.

False

Choose whether each of the following statements is true or false. An object at rest has no forces acting on it.

False

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. M3 accelerates upwards.

False

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The magnitude of V3 can be -4.0 m/s

False

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The magnitude of V3 can be 0.0

False

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The magnitude of V3 can be 8.0 m/s

False

which of the following could be mass densities? m^2b/l1*l2

False

which of the following could be mass densities? (True or False) ma*mb/l1*l2

False

A car accelerates from rest to a certain velocity in a certain time. Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)? Half the time. Same time. Double the time. Four times the time.

Four times the time.

A ball is thrown straight up into the air with an initial vertical velocity, v. It rises to a height, h. The graphs below are plots of energy as a function of height. Match each description to the correct graph. C / D--- A \ B U E The ball's kinetic energy as a function of its height after release.

Graph A

A ball is thrown straight up into the air with an initial vertical velocity, v. It rises to a height, h. The graphs below are plots of energy as a function of height. Match each description to the correct graph. C / D--- A \ B U E The ball's gravitational potential energy as a function of its height after release.

Graph C

A ball is thrown straight up into the air with an initial vertical velocity, v. It rises to a height, h. The graphs below are plots of energy as a function of height. Match each description to the correct graph. C / D--- A \ B U E The ball's total mechanical energy as a function of its height after release.

Graph D

How long would it take to reach the same velocity if the engine had twice the power? Half the time. Same time. Double the time. Four times the time.

Half the time.

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. T3 is ... T2.

Less than

How does the magnitude of the net work on A compare to the magnitude of the work of the hand on A? Magnitude of the work by the hand on A is larger Magnitude of the net work on A is larger Same

Magnitude of the work by the hand on A is larger

Which one of the following is not a unit? (Newton, Kilometer, Kelvin, Momentum)

Momentum

How does the magnitude of the net work on A compare to the magnitude of the net work on B? More net work on A More net work on B Same

More net work on A

Using the standard physical meanings of the quantities t, x, v, and a, choose which of the following equations are dimensionally consistent. x=v/2a

Not Consistent

which of the equations are dimensionally consistent? v=at^2/2

Not Consistent

Two blocks A and B (mA>mB) are pushed for a certain distance along a frictionless surface. How does the magnitude of the work that A does on B compare to the magnitude of the work that B does on A? Same (and not zero) The magnitude of the work of B on A is larger The magnitude of the work of A on B is larger Both zero

Same (and not zero)

Suppose m1 and m2 are increased by the same additive factor (in other words, each mass has the same amount of extra mass added to it). What happens to the acceleration of the system? The acceleration is unchanged. The acceleration decreases. The acceleration increases. The acceleration may increase, stay the same, or decrease, depending on how much mass is added.

The acceleration decreases.

Consider the system known as Atwood's Machine (two masses hanging over a pulley. Assume the two masses m1 and m2 are not equal. Suppose m1 and m2 are increased by the same multiplicative factor (in other words, each mass is multiplied by the same number). What happens to the acceleration of the system? The acceleration is unchanged. The acceleration decreases. The acceleration increases. The acceleration may increase, stay the same, or decrease, depending on the size of the multiplicative factor.

The acceleration is unchanged.

Now you want to make the sled speed up as indicated. What does the magnitude of the required pulling force not depend on? The current velocity of the sled The coefficient of kinetic friction between the sled and the floor The mass of the sled The angle at which you pull

The current velocity of the sled

Again, suppose m1 and m2 are increased by the same multiplicative factor. What happens to the tension in the rope? The tension may increase, stay the same, or decrease, depending on the size of the multiplicative factor. The tension decreases. The tension is unchanged. The tension increases.

The tension increases.

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The average velocity is zero.

True

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The initial speed and final speed are equal.

True

A baseball is thrown vertically upwards into the air (neglect air resistance) and returns to the starting point. (True or False) The total displacement is zero.

True

A cart of mass m can move without friction on an airtrack. Initially, it is at rest. Then, for a limited time t , it is pushed down the track with a constant force F. Which of the following statements are true. When you stop pushing, the cart will continue moving at the same speed.

True

A cart of mass m can move without friction on an airtrack. Initially, it is at rest. Then, for a limited time t , it is pushed down the track with a constant force F. Which of the following statements are true? While the cart is pushed, it has a constant acceleration.

True

Choose whether each of the following statements is true or false. An object with a nonzero acceleration at some instant of time can have a velocity of zero at that instant.

True

Choose whether each of the following statements is true or false. An object with a nonzero velocity can have an acceleration of zero.

True

Choose whether each of the following statements is true or false. An object can be in motion and still have zero net force acting on it.

True

Choose whether each of the following statements is true or false. An object can be moving in one direction while the net force acting on it is in another direction.

True

For this example, let ma and mb be masses l1, l2, l3 and x be lengths t1 and t2 be times A mass density is defined as mass per volume, and a volume has a dimension of [L]3. Which of the following could be mass densities? (True or False) ma/l1*l2*l3

True

In the figure to the right, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There is friction between the horizontal plane and M2 (Mk not = 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. The magnitude of the net force on M2 is 0.

True

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The magnitude of V3 can be 6.0 m/s

True

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The magnitude of V3 can be 7.0 m/s

True

The velocity vector V1 has a magnitude of 4.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 3.0 m/s. The sum of the two is V3 , so that V3= V1 + V2 (True or False) The x-component of V3 can be 4.0 m/s

True

which of the following could be mass densities (True or False) ma/l^21*l^22*x

True

What is the magnitude of the velocity of the object at the highest point of the trajectory? 0 VocosӨ Vo VosinӨ

VocosӨ

The plot shows the trajectory (height versus distance) of an object launched at an angle of =69.7 degrees with the horizontal and an initial speed . What is the magnitude of the acceleration of the object at the highest point of the trajectory? gsinӨ g gcosӨ 0

g

You jump out of an airplane, and your parachute opens after a brief period of free fall. In order to slow your fall, the parachute must exert a force that is equal to your weight. less than your weight. greater than your weight.

greater than your weight.

A sled (mass 320 kg) is pulled across a stone floor with a coefficient of kinetic friction of 0.7. The rope that is used to pull it is at an angle a of 30 degrees with the horizontal. When the sled moves at a constant velocity (i.e., no acceleration), the normal force that the floor exerts on the sled is ... equal to the sled's weight. lower than the sled's weight. higher than the sled's weight.

lower than the sled's weight.

What is the tension of the cable? mhook+mload*g+a mhook*g+mhook*a mhook+mload*g-a mhook*a mhook*g-a mhook(g+a) mhook*g mload*g+mhook*a

mhook+mload*g+a

A barrel (mass mLoad) is attached to a massless rope, which is attached to a hook (mass mHook), which is attached to the massless cable of a crane. The cable is accelerating up with an acceleration a. What is the tension of the rope? mhook+mload*g-a mload*g+mload*a mhook+mload*g+a mhook*g+mload*g+a mload*a mload*g+mhook*a mload*g mhook*g-a

mload*g+mload*a