Motion Speed Force

When a constant unbalanced force acts on an object in the direction of the motion, what initially happens to the object's speed?

• It decreases.

• It increases.

• It decreases then increases.

• It remains the same.

What term represents the strength of a force?

• direction

• inertia

• friction

• magnitude

Terrell runs the 100 m race at a speed of 9 m/s. Jason asked Terrell to time him while he ran the 100 m. Jason's time was 12 seconds. Does Jason run faster than Terrell?

• No. Jason's average speed is 8.3 m/s.

• No. Jason's average speed is.12 m/s

• Yes. Jason's average speed is 12.0 m/s.

• Yes. Jason's average speed is 11.1 m/s.

How is the acceleration of an object traveling in a straight line determined?

• The time it took the object to travel is divided by the distance the object traveled during that time.

• The distance the object traveled is divided by the time it took the object to travel the distance.

• The amount of time it takes the object to change speed is divided by the average speed of the object.

• The change in the speed of the object is divided by the amount of time in which the change occurred.

Under what condition will a bowling ball slow down if it is rolling down a bowling lane at a constant speed?

• The mass of the ball is reduced.

• The direction of the ball is changed.

• An accelerating force is applied to the ball.

• An unbalanced external force is applied to the ball.

Examine the image of the forces acting on a cart.

Which additional force can be applied to make the cart move in the opposite direction?

• 60 N towards the west

• 40 N towards the west

• 40 N towards the east

• 60 N towards the east

What will happen to an object in motion with no unbalanced force acting on it?

• It will continue to accelerate until it reaches the speed of light.

• It will gradually slow down and come to a rest.

• It will continue to move at a constant speed.

• It will initially accelerate but gradually slow down until it comes to a rest.

A person goes for a jog at a park. The person’s motion is shown in the graph.

• The person stands still for 5 s, then jogs at

  a constant velocity for 3 s.

  The person rests for 2 s before returning

  back to the starting point 10 s later.

• The person jogs at a constant velocity for 5

  s, then stands still for 3 s.

  The person jogs faster for 2 s before

  stopping for a 10 s break.

• The person jogs at a constant velocity for 5

  s, then jogs faster for 3 s.

  The person jogs at a constant velocity for 2 s

  before jogging faster back to the starting

  point 10 s later.

• The person stands still for 5 s, then

  accelerates at an increasing velocity for 3 s.

  The person rests for 2 s before returning

  back at a faster velocity to the starting

  point 10 s later.

Lee pushes on a wall to stretch after a long run. He pushes on the wall with 20 N of force, yet the wall does not move. Which term best describes the forces in this scenario?

• unbalanced forces

• gravitational forces

• directional forces

• balanced forces

A desk weighing 200 N rests on the floor. How much force does the floor apply to the desk?

• 0 N

• less than 200 N

• 200 N

• more than 200 N