AP Physics Elevator Problems

Two blocks of wood, each of mass 2 kg, are suspended from the ceiling by strings of negligible mass, as shown above.What is the tension in the upper string?

• 10 N

• 20 N

• 40 N

• 50 N

• 60 N

Tags

NGSS.HS-PS2-1

Two blocks of wood, each of mass 2 kg, are suspended from the ceiling by strings of negligible mass, as shown above.What is the force exerted on the upper block by the lower string?

• zero

• 10 N upward

• 10 N downward

• 20 N upward

• 20 N downward

Tags

NGSS.HS-PS2-1

A block of mass 2 kg is suspended from a rope, as shown above. If the tension in the rope is 10 N, the acceleration of the block is most nearly

• zero

• 2 m/s² up

• 2 m/s² down

• 5 m/s² up

• 5 m/s² down

Tags

NGSS.HS-PS2-1

Two blocks of masses m and M are suspended as shown above by strings of negligible mass. If a person holding the upper string lowers the blocks so that they have a constant downward acceleration, the tension in the string at point P is

• (M+m)g-ma

• (M+m)g-Ma

• Mg-(M+m)a

• Mg

• M(g-a)

Tags

NGSS.HS-PS2-1

A 50-kg student stands on a scale in an elevator. At the instant the elevator has a downward acceleration of 1.0 m/s² and an upward velocity of 3.0 m/s, the scale reads approximately

• 350 N

• 450 N

• 500 N

• 550 N

Tags

NGSS.HS-PS2-1

A rope of negligible mass supports a block that weighs 30 N, as shown above. The breaking strength of the rope is 50 N. The largest acceleration that can be given to the block by pulling up on it with the rope without breaking the rope is most nearly

• 6 m/s²

• 6.7 m/s²

• 10 m/s²

• 15 m/s²

• 16.7 m/s²

Tags

NGSS.HS-PS2-1

A mass is suspended from the roof of an elevator by means of a spring balance. The elevator is moving upwards and the readings of the spring balance are noted as follows:

Speeding up: R_U

Constant speed: R_C

Slowing down: R_D

Which of the following is a correct relationship between the readings?

• R_U >R_C

• R_U = R_D

• R_C =R_D

• R_C< R_D

Tags

NGSS.HS-PS2-1

Two blocks are connected by a rope, as shown above. The masses of the blocks are 5 kg for the upper block and 10 kg for the lower block. An upward applied force of magnitude F acts on the upper block.

Question

The system is moving and accelerating upward. A pair of scissors cuts the rope. Which of the following describes the motion of the 10 kg block immediately after the rope has been cut?

• The block continues to move upward and to accelerate upward.

• The block begins to move downward but continues to accelerate upward.

• The block continues to move upward but begins to accelerate downward.

• The block begins to move downward and to accelerate downward.

Tags

NGSS.HS-PS2-1

Two blocks are connected by a rope, as shown above. The masses of the blocks are 5 kg for the upper block and 10 kg for the lower block. An upward applied force of magnitude F acts on the upper block.

Question

If the net acceleration is downward but has a magnitude less than g, then which has the larger magnitude, the force F or the tension in the rope?

• The tension in the rope

• Force F

• Neither. They have equal but nonzero magnitudes.

• Neither. They have equal zero magnitudes.

Tags

NGSS.HS-PS2-1

Two blocks are connected by a rope, as shown above. The masses of the blocks are 5 kg for the upper block and 10 kg for the lower block. An upward applied force of magnitude F acts on the upper block.

Question

If the F = 180 N, what is the tension in the rope?

• 120 N

• 100 N

• 220 N

• 200 N

Tags

NGSS.HS-PS2-1