Tag Archives: Velocity

A2L Item 276

Goal: Unspecified.

Source: Unspecified.

A pendulum is released from rest at position A and swings toward the
vertical under the influence of gravity as depicted below.

When at position B, which direction most nearly corresponds to the
direction of the acceleration?

Enter (9) if the direction cannot be determined.


Commentary:

None provided.

A2L Item 275

Goal: Unspecified.

Source: Unspecified.

Two cars have a race. Car A drives with constant speed of 20 m/s. Car B
drives with speed 10 m/s for 3 s, then accelerates uniformly to a speed
of 25 m/s during the next 3 s. Car B maintains the speed of 25 m/s for
the rest of the race.

What is the minimum length of race if Car B is to overtake car A?


Commentary:

None provided.

A2L Item 274

Goal: Unspecified.

Source: Unspecified.

Two cars have a race. Car A drives with constant speed of 20 m/s. Car B
drives with speed 10 m/s for 3 s, then accelerates uniformly to a speed
of 25 m/s during the next 3 s. Car B maintains the speed of 25 m/s for
the rest of the race.

If the race is very long, can car B ever catch car A?

  1. YES
  2. NO
  3. Not enough information.

Commentary:

None provided.

A2L Item 273

Goal: Unspecified.

Source: Unspecified.

Jane is riding in a hot air balloon that is rising vertically at a
constant speed of 3 m/s over a lake. She reaches out and drops a rock
from the balloon when the distance from the rock to the water is 50 m.
Use g=10 m/s2, and let the up direction be positive. About
how long after Jane drops the rock will it splash into the water?

  1. 2.0 sec
  2. 2.6 sec
  3. 3.5 sec
  4. 5.0 sec
  5. 6.8 sec
  6. 8 sec


Commentary:

None provided.

A2L Item 272

Goal: Unspecified.

Source: Unspecified.

Jane is riding in a hot air balloon that is rising vertically at a
constant speed of 3 m/s over a lake. She drops a rock from the balloon
when the distance from the rock to the water is 50 m. Use g=10
m/s2, and let up be the positive direction. Assume the origin
is on the surface of the water, what is the initial position of the
rock?

  1. 0
  2. 50 m
  3. -50 m
  4. None of the above.

Commentary:

None provided.

A2L Item 271

Goal: Unspecified.

Source: Unspecified.

Jane is riding in a hot air balloon that is rising vertically at a
constant speed of 3 m/s over a lake. She drops a rock from the balloon
when the distance from the rock to the water is 50 m. Use g=10
m/s2, and let up be the positive direction. What is the
initial velocity of the rock?

  1. 3 m/s
  2. -3 m/s
  3. 0
  4. Cannot be determined.
  5. None of the above.

Commentary:

None provided.

A2L Item 270

Goal: Unspecified.

Source: Unspecified.

A person throws a ball straight up. The ball rises to a maximum height
and falls back down so that the person catches it. When is the
acceleration of the ball at its MAXIMUM?

  1. Just after it leaves the person’s hand.
  2. At its maximum height.
  3. Just before the person catches it.
  4. Both 1 and 3.
  5. None of the above.

Commentary:

None provided.