1. Mrs. Esposito

2. Rules of the Game Create an answer sheet with your name Each member of each group should have their own answer sheet. Each group gets a chance to answer the question. When the question is read, discuss with group members….every student must write down the answer on the answer sheet. When you are SURE of the answer, have your team leader stand up. I will pick one person in your group and read from their answer sheet…by the way, all work must be shown or you won’t receive credit. Every team that gets the problem right on the first try gets two points; On the second try gets one point. First place team gets three points. There is a time limit. No notes or textbooks allowed during the activity!

3. Rules of the Game Listen attentively to correct answers and as questions are explained! Talking during explanations or while another team is answering results in a 5-point deduction. Arguing with the referee (Mrs. E) will result in a 5-point deduction from your group’s total. Units are a part of the answer. Don’t forget them!!!

4. Grading All students who participate fully in this activity and contribute positively to their teams earn a 10 point out of 10 point lab grade. 1 st place team earns 11 out of 10 points on this lab grade. 2 nd place team earns 10.5 out of 10 points on this lab grade.

5. 1. As the object moves from point A to point D across the surface, the sum of its gravitational potential and kinetic energies ____. a. decreases, only b. decreases and then increases c. increases and then decreases d. remains the same 2. The object will have a minimum gravitational potential energy at point ____. 3. The object will have minimum kinetic energy at point _____. Problem 1

6. A block of mass 18.0 kg is sliding down an 6.0 metre long ramp inclined at 56.0 deg. to the horizontal. Calculate the speed at the bottom assuming the ramp is frictionless. Calculate the speed at the bottom assuming the ramp has a coefficient of friction of 0.20. Problem 1b

7. At the end of the Shock Wave roller coaster ride, the 6000-kg train of cars (includes passengers) is slowed from a speed of 20 m/s to a speed of 5 m/s over a distance of 20 meters. Determine the braking force required to slow the train of cars by this amount. Problem 2

8. A 1000-kg car traveling with a speed of 25 m/s skids to a stop. The car experiences an 8000 N force of friction. Determine the stopping distance of the car. Problem 3

9. Use the law of conservation of energy (assume no friction) to fill in the blanks at the various marked positions for a 1000-kg roller coaster car. Problem 4

10. During a certain time interval, a 20-N object free-falls 10 meters. The object gains _____ Joules of kinetic energy during this interval. Problem 5

11. A tired squirrel (mass of approximately 1 kg) does push-ups by applying a force to elevate its center-of- mass by 5 cm in order to do a mere 0.50 Joule of work. If the tired squirrel does all this work in 2 seconds, then determine its power. Problem 6

12. When doing a chin-up, a physics student lifts her 42.0- kg body a distance of 0.25 meters in 2 seconds. What is the power delivered by the student's biceps? Problem 7

13. A 10-N force is applied to push a 5 kg block across a frictional surface at constant speed for a displacement of 5.0 m to the right. Calculate the work done by each individual force (work done by friction, work done by gravity, work done by normal force, work done by applied force). Calculate the net work done on the block. Problem 8

14. Calculate the work done by a 2.0-N force (directed at a 30° angle from the horizontal) to move a 500 gram box a horizontal distance of 400 cm across a frictionless floor at a constant speed of 0.5 m/s. (HINT: Be cautious with the units.) Problem 9

15. A 900-kg compact car moving at 60 mi/hr has approximately 320 000 Joules of kinetic energy. Estimate its new kinetic energy if it is moving at 30 mi/hr. (HINT: use the kinetic energy equation as a "guide to thinking.")guide to thinking Problem 10

16. Bruce grasps the end of a 20.0 m long rope attached to a tree and swings. If the rope starts at an angle 35 degrees with the vertical, what is Bruce's speed at the bottom of the swing? Problem 11

17. A 200 g mass is attached to a spring of spring constant k. The spring is compressed 20 cm from its equilibrium value. When released the mass reaches a speed of 5 m/s. What is the spring constant (in N/m)? Problem 12

18. A rail car of mass 4000 kg rolls downhill on tracks and on to a level section of tracks 8 m in elevation lower than the starting point. At the end of the tracks is a spring with spring constant 600000 N/m. Ignoring friction, what is the maximum compression of the spring in stopping the car? Problem 13

19. A 130 N suitcase is dragged a distance of 250m at a constant speed. A force of 60 N is exerted at an angle 40 degrees above the horizontal. a. How much work is being done? b. How much work is done by friction? Problem 14

20. A 0.600-kg particle has speed of 2.00 m/s at point A and kinetic energy of 7.50 J at point B. What is a. its kinetic energy at A? b. its speed at B? c. the total work done on the particle as it moves from A to B? Problem 15

21. A 25-kg box slides, from rest, down a 9.0-m-long incline that makes an angle of 15° with the horizontal. The speed of the box when it reaches the bottom of the incline is 2.4 m/s. a. What is the coefficient of kinetic friction between the box and the surface of the incline? b. How much work is done on the box by the force of friction and c. What is the change in the potential energy of the box? Problem 16

22. A compressed spring that obeys Hooke's law has a potential energy of 18 J. If the spring constant of the spring is 400 N/m, find the distance by which the spring is compressed. Problem 17

23. At a constant speed of 30 m/s, the average frictional force on a light car is 1050 N. What power must the motor generate to maintain this speed? A free body diagram will help. Problem 18

24. Problem 19 The green block is falling at a speed of 29 m/s and is 14 meters above the spring. The spring constant is 4000 N/m, To the nearest tenth of a cm how far is the spring compressed?

25. Honors Only Calculate the work done on a 1000 kg car over the 30 meter distance. If the car starts from 2 m/s, how fast is it moving after it experienced the work from the graph above. Problem 20