physics summative

What force is responsible for causing a change in an object's motion?

• Unbalanced force

• Balanced force

• Gravitational Force

• Frictional Force

• Static friction

In the scenario depicted in the figure on the right, where an elevator is ascending at a constant speed with the assistance of a steel cable and negligible frictional effects, how can the forces be best described among the following alternatives?

• A

• B

• C

• D

• E

What kind of force is present when two objects are in contact with each other?

• Balanced force

• Unbalanced force

• Contact force

• Non-contact force

• Gravitational force

A spaceship is freely drifting in outer space without any external forces acting on it. At the specific moment denoted as 10, the spacecraft activates its engine, applying a constant force in the direction of its motion. At time 18, the spacecraft's engine is deactivated.

During the time interval _to to _tg the speed of the spaceship is:

• Constant for a while and decreasing thereafter

• Increasing for a while and constant thereafter

• Continuously decreasing

• Continuously increasing

• Constant

In the previous question, the spaceship's engine is turned off at the instant of time _ts. After this, the speed of the spaceship is

• Constant for a while and decreasing thereafter

• increasing for a while and constant thereafter

• Continuously decreasing

• Continuously increasing

• Constant

In the face of a powerful wind, a tennis player successfully strikes a tennis ball with her racket, sending it over the net and into her opponent's court.

How can the forces acting on the tennis ball be best described during the moment after it has separated from the racket and before making contact with the ground among the following alternatives?

• A

• B

• C

• D

• E

A woman exerts a constant horizontal force on a large box. As a result, the box moves across a horizontal floor at a constant speed v0. If the woman doubles the horizontal force that she exerts on the box to push it on the same horizontal floor, the box then moves:

• for a while with a constant speed that is greater than the speed v0. then with a speed that increases thereafter

• for a while with an increasing speed, then with a constant speed thereafter

• with a continuously increasing speed.

• with a constant speed that is greater than the speed w, but not necessarily twice as great,

• with a constant speed that is double the speed v0

An elevator is being lifted up an elevator shaft at a constant speed by a steel cable as shown in the figure. All frictional effects are negligible. Which of the following describes. the forces in this situation?

• A

• B

• C

• D

• E

Despite a very strong wind, a tennis player manages to hit a tennis ball with her racquet so that the ball passes over the net and lands in her opponent's court. Which of the following forces is (are) acting on the tennis ball after it left contact with racquet and before it touches the ground?

• only a downward force of the gravity

• a downward force of the gravity and a force by the "hit"

• a downward force of the gravity and a force exerted by the air

• a force by the "hit" and a force exerted by the air

• a downward force of the gravity, a force by the "hit" and a force exerted by the air

The figures below show three cases in which a rigid rod of length 2L is acted upon by some forces and is free to rotate at the center. All forces labeled F have the same magnitude. Which case/s have a net torque?

• A

• B

• C

• D

• E