Force & Motion Lesson 1-4 Practice

If a lizard can run 12 m across the water in 4 seconds, how fast is he traveling? (Hint: Speed = Distance/Time)

• 2 m/s

• 3 m/s

• 2 seconds

• 34 meters

Tags

speed

This motion graph represents:

• object at constant speed

• acceleration

• object at rest

• slowing down

Tags

describing motion

distance/time graphs

speed

Which tells the VELOCITY of an object?

• 75 mph

• 75 mph south

Tags

describing motion

velocity

What is the definition of acceleration?

Choose 1 correct answer.

• Speed with a direction

• A constant speed over time

• The change in velocity's rate

• Returning to the original position

Answer explanation

When graphing motion, acceleration is represented by a line on a velocity/time graph.

A positive slope on a velocity time graph represents acceleration because the velocity is changing over time---the velocity is increasing.

A negative slop on a velocity/time graph represents deceleration (or negative acceleration) because the velocity is changing over time--the velocity is decreasing

Tags

describing motion

acceleration

velocity/time graphs

A flat line of a velocity-time graph represents __________.

Choose all that apply.

• positive acceleration

• constant velocity

• negative acceleration

• no acceleration

Answer explanation

Letter B represents a constant velocity or no acceleration because from 20s-40s, the velocity stays the same (constant) at 40 m/s

Tags

describing motion

acceleration

velocity/time graphs

What are examples of acceleration?

Choose all that apply.

• a bus speeding up

• sitting in class working on Exact Path

• a falcon changing direction to catch its prey

• slowing down in the hallway to stop at your locker

Answer explanation

Lesson 4 on the Acceleration Notes. Acceleration is a change in velocity's rate (in speed or direction).

a bus speeding up---> = increasing velocity

a falcon changing direction--> =changes direction

slowing down in hallway---> = decreasing velocity

Tags

acceleration

Explain the motion from 1-3s.

Choose all that apply.

• Not moving

• Constant velocity

• Changing acceleration

• no acceleration

Tags

describing motion

acceleration

velocity/time graphs

Explain the motion from 3-5s.

Choose all that apply.

• Not moving

• Positive Acceleration

• Increase in velocity

• Non-constant acceleration

Answer explanation

On a velocity/time graph, the positive slope represents an increase in velocity. As time increases, velocity also increases.

On a distance/time graph, the positive slope means the object is covering a distance at a constant speed and the object is moving away from the starting point.

Tags

describing motion

acceleration

velocity/time graphs

Explain the motion from 5-7s.

Choose all that apply.

• Deceleration

• Constant speed

• Negative Acceleration

• Decrease in velocity

Answer explanation

At 5s-7s the line has a negative slope. A negative slope on a velocity graph is a decrease in velocity because as the line moves downward, the velocity also decreases. At 5 s, the velocity is 12m/s; at 6 s the velocity is 10m/s; at 7 s the velocity is 8 m/s

Tags

describing motion

acceleration

velocity/time graphs

What does the line on a velocity/time graph indicate?

Choose 1 correct answer.

• acceleration

• speed

• velocity

• direction of travel

Answer explanation

The line on a velocity/time graph is acceleration.

The line on a distance/time graph is speed.

Extension:

the x and y axis for the distance time graph are represented as Velocity on the Velocity/Time graph

Tags

describing motion

acceleration

velocity/time graphs