Please make sure the answer is in the correct units. (mJ) You have a level track
ID: 1557739 • Letter: P
Question
Please make sure the answer is in the correct units. (mJ)
You have a level track. You push a cart with mass = 0.76 [kg] You measure the initial velocity to be 0.58[m s^-1] 2 seconds later, you measure the velocity to be 0.435 [m s^-1] What is the work (reported in mJ) that friction did on the cart? work = [mJ] Use three sig. figs. or N/A if not enough information is given, such as change in position! Remember, that if the system gains energy, then positive work is done, otherwise the system loses energy rightarrow work done on systemExplanation / Answer
from Work Energy theorem
W = change in KE
W = 0.5 m (Vf^2 - Vi^2)
W = 0.5 * 0.76 * (0.435^2 - 0.58^2)
W = -0.0559 Joules or 56 m Joules