**Forces Test Review Packet**

**Complete all the review problems by WED. 5/27**

**Test Date: THUS. 5/28/15**

**Essential Questions**

- How are distance, time and speed related?
- How does motion change?
- How do forces affect motion?

Suggestions:

- Reread lessons 1 through 3 (pages 5- 41)
- Look at past quizzes, labs, worksheets, and notes

**Know and be able to define the following words:**

Vector / Motion / Velocity

Acceleration /

**Centripetal acceleration**/ Force

Net force / Inertia / Newton

**Newton’s First Law**/

**Newton’s Second Law**/

**Newton’s Third Law**

Review Part I

**Lesson 1: Know how to calculate distance, time and speed. Use the formula speed = distance ÷ time**

Max chases a ball around the back yard and travels at a speed of 16 m/s for 5 seconds. What distance does he travel?

Sylvester Snail crawls at a speed of 12 mm/minute for a distance of 110 millimeters. How much time does it take him to travel this distance?

Leah drives to California and covers a distance of 4,100 miles in 55 hours. What is her average speed?

Mike leaves his house at 6:30 AM and arrives at his sister’s house at 11:00 AM. What is his average speed in mi/hr if he traveled 300 miles?

**Lesson 2: Know how to calculate acceleration both positive and negative.**

- A car is at rest and accelerated to 70 miles/hr. in 0.25 hours. What is its acceleration?

- A sprinter is running at a speed of 12 m/s and slows to a stop in 8 seconds. What is the acceleration?

- Mrs. Simon’s dog, Oscar, chases a ball at a speed of 15 m/s and slows down to 3 m/s to retrieve it. He slows down in 4 seconds. What is his acceleration?

- Define centripetal acceleration and give a real life example of where you would see it.

**Lesson 3: Know how to calculate net force and how to use Newton’s three laws of motion.**

Net force = /

Net force =

Net force = 12 N left

A= /

Net force = 52 N right

B =

5. A woman pushes a stalled car. The woman pushes with a force of 88 N. What is the mass of the car if the car accelerates at 5 m/s2? SHOW ALL WORK.

6. . A 2130 kg car accelerated at a rate of 4.0 m/s2. How much force is the car’s engine producing? SHOW ALL WORK.

7. Bill pushes a 40 kg box with a force of 500 N. What is the acceleration of the box?

8. John is pulling a 7 kg box with a 95 newton force. What acceleration will it have?

**Motion & Newton's Laws Review Part II **

- If two objects have different masses, which object is easier to accelerate? Which law supports your answer?
- The tendency of an object to resist change in its motion is known as______.
- Speed equals distance divided by______.

- \\\
- On a graph showing distance versus time, a horizontal line represents an object that is______.

- Give an example of negative acceleration:

- If a bicyclist travels 30 kilometers in two hours, her average speed is ______

- In speed-versus-time graph, a straight line shows that acceleration is______
- A person traveling in a car that stops suddenly keeps moving forward due to ______.
- If the action force of a bat striking a ball accelerates the ball in one direction, the reaction force accelerates the

bat in the ______direction. - A roller coaster is moving at 10 m/s at the top of a hill and 22 m/s at the bottom of the hill two seconds later. What is the average acceleration?

______ - To describe velocity you need to know ______and______.
- The total distance traveled divided by the total time taken to travel the distance is ______.
- If your speed changes from 10 km/h to 6 km/h, you have ______acceleration.
- Newton's first law of motion states that an object remains at rest unless a(n) ______force acts on it.
- The statement "for every action, there is an equal but opposite reaction" is a statement of

______law. - When a swimmer pushes the water back, the water pushes the swimmer forward. What is the reaction force to in this situation?

- If you push a skateboard that has a mass of 60kg with a force of 6N, what force will the skateboard push back

on you according to Newton’s third law of motion? ______ - Forces that are equal in size but opposite in direction & cause no change in motion are

______. - Draw a distance/time graph that shows the motion of a person who left home, sat on a park bench for a while and then walked home at a constant speed?

21. How far did Kathy jog in the first 4 minutes?

22. What is Kathy’s average speed? Show your work.

- How would you describe Kathy’s motion?

24. Describe Rachel’s motion at 9 minutes.

25. If Rachel’s motion from 2 to 7 seconds had continued, what would have been her distance at 10 seconds?

26. What is the motion of an object with zero acceleration?______

27. What is the acceleration formula?

28. If a family took a vacation and was traveling 60m/h, how far would they have traveled after 3 hours? ______

29. Draw a velocity/time graph that represents positive acceleration

30. Which ball has the fastest acceleration?

31. What happened to the speed of ball B during the final two seconds?

32. What does the line segment on the graph from 0 to 3 seconds represent for ball B?