Question

Please show your work! Thanks

Use the KE vs. TIME graph below to answer the following questions. Express all answers in the appropriate mks units. KE vs. TIME GRAPH KE (1) A.) Identify when the object was not moving. 15 s X 404 B.) Over what period of time was the object speeding up? to 15 s 10 s 30 C.) Over what period of time was the object slowing down? Os to 10 s D.) Over what period of time was the object maintaining a constant speed? 15 s to 25 s 20 E.) Determine the work done during the following 3 time frames: 0 to 10 s → -10 J 10 to 15 s →-5 J 15 to 25 s + 5J x 10 F.) Determine the total work done. OJ X t(s) G.) Determine the power at the following 3 times: 9.5 s + 0 X Units are required for this answer. 13.5 s → 22 s → 10 15 20 25

Answer 1

A. object here is never at rest because velocity is always present which cause kinetic energy remains always associated with the body hence object never comes to rest till 25 sec.

E.

0 to 10 sec

W = KEf - KEi = 4J - 16 J = - 12J

10 to 15 sec

W = KEf - KEi = 8- 4 = 4 J

15 to 25

W = KEf - KEi = 8 -8 = 0J

F. Total work done = change in kinetic energy

Also work done doesn't depends on the path of the body it just depends on the initial and final position so that ,

Wt = 8- 16 = - 8 J

G. Power is given as P = energy/time,

At 9.5 second

P= 4. 5J/9.5 sec= 0.4736 J/s

At 13.5 second

P = 6.5J /13.5 = 0.48148 J/s

At 22 sec

P = 8/22 = 0.3636 J/s

Note in mks system unit of power is J/s