Warm-Up Thurs 4/12/12 On a graph, the steeper the slope, the _______ the speed. 2. What does a flat, horizontal line mean on a distance vs. time graph?

Force & Motion Review

Which one of Newton’s Laws would best fit this situation? Question 1 Which one of Newton’s Laws would best fit this situation? Alec pushes a 50 kg box across the floor with a force of 20 N. Later that day he pushes a 30 kg box with the same force. Because the second box is less massive, it will have a greater acceleration. Law 1 Law 2 Law 3

Which of the following is true about acceleration? Question 2 Which of the following is true about acceleration? Acceleration is speed in a given direction. Acceleration is a change in either speed or direction. Acceleration is distance travelled in a given amount of time. all of the above

Question 3 A book sitting still on a table is exerting 10 N of force onto the table. According to Newton’s 3rd Law, how much force will be exerted back onto the book? 20 N 0 N 5 N 10 N

Which of Newton’s Laws would best explain this scenario? Question 4 Which of Newton’s Laws would best explain this scenario? Dude and Guy are dressed as giant sumo wrestlers and are running towards each other. Once they hit, they immediately bounce off each other. First Law Second Law Third Law

Question 5 What is happening in this distance vs time graph? A. Hesoo moves at a constant speed B. Hesoo moves one direction and then speeds up in the opposite direction. C. Hesoo moves in one direction, remains at rest, and then moves in the opposite direction D. Hesoo has no acceleration

Question 6 Which statement best summarizes the scientific concept shown in the cartoon? A falling body accelerates at a constant speed. B. The motion of an object is constantly changing due to magnetic forces. C. The force of friction causes an object in motion to move faster. D. A body in motion will remain in motion unless influenced by an outside force.

Question 7 With what force does a 7 kg bowling ball with an acceleration of 4.0 m/s2 strike the pins? 28 N 3 N 1.75 N 32 N

Question 8 Andrew traveling south at 80 miles per hour is an example of: Speed Velocity Acceleration Friction

Question 9 If all the forces acting on a moving object are balanced, then the object will: A. slow down and stop B. change the direction of its motion C. accelerate D. continue moving at a constant velocity

Question 10 The tendency of a moving object to continue in a straight line or of a stationary object to remain in place is called: Gravity Friction Inertia Force

Question 11 A car traveling at 90 mph hits a brick wall. The person inside the car was not wearing a seat belt. The person will continue to move even though the car has stopped. This is best explained by: Newton’s First Law Newton’s Second Law Newton’s Third Law Gravity

Which of Newton’s Laws would best fit this situation? Question 12 Which of Newton’s Laws would best fit this situation? Max drops a ping pong ball on the table. The ping pong ball hits the table and then bounces back up. Law 1 - Inertia Law 2 – F=MA Law 3 – Action/Reaction

Question 13 On what section of the racetrack will the forces on the cars be balanced? A. the starting block B. the ramp only C. the level section after the ramp D. the entire track

Question 14 What is the correct statement about the object represented by the graph? The object is speeding up. The object is slowing down. The object is moving at a constant speed. The object is changing direction.

Question 15 Brian flicks a penny across the floor of his classroom. Newton’s law of Inertia says the penny will continue to move until acted on by an unbalanced force. What force is slowing the penny down? Friction Stretching Forces Gravity None. The forces are balanced

Question 16 A bird is flying through the air. The wings of a bird push air downward. Because of Newton’s 3rd Law, the air must also be: Pushing his wings downward Pushing the bird forward Pushing his wings at a constant speed Pushing his wings upward

Question 17 A toy car travels 4 meters across the floor in 3.2 seconds. What is the speed of the car? Speed = Distance/Time 12. 5 m/s 1.25 m/s 12.8 m/s 0.3 m/s

Question 18 If a force of 5 N is placed on an object with a mass of 2 kg, what would the object’s acceleration be? 10 m/s2 2.5 m/s2 25 m/s2 0.4 m/s2

Question 20 Clark rode his bicycle 24 meters to his friend’s house down the block. It took him 2 minutes to arrive at his friend’s house. What was Clark’s average speed? 24 meters/minute 12 meters/minute 48 meters/minute 2 meters/minute

Question 21 Lunchbox rode his jet ski 50 meters south in 10 seconds, and then went east another 100 meters in the same amount of time. Which of the terms below can best be used to describe these changes? (You may use more than one) I. Speed II. Velocity III. Acceleration

Question 22 Marissa’s family traveled 480 kilometers in six hours. At what point in the trip were they traveling the slowest? Between hour 0 and 1 Between hour 1 and 2 Between hour 3 and 4 Between hour 5 and 6

Write a short paragraph (2-5 sentences) answering the following: How do speed, velocity, and acceleration differ? How are they calculated?