Work, Power and EnergyHard
Question
A block of mass 10 kg is moving in x-direction with a constant speed of 10m/sec it is subjected to a retarding force F= - 0.1 x joule/metre during its travael from x=20 metre to x = 30 metre. Its final kinetic energy will be
Options
A.475joule
B.450joule
C.275joule
D.250joule
Solution
We know that, Change in kinetic energy = work done on the object by force
Here, work done = Fdx =
0.1x dx
= 0.1
[302 - 202]
= 0.05[900 - 400] = 0.05 × 500 = 25 jouleNow, initial kinitic energy
10 × 100 = 500 joule
Here, work done = Fdx =
0.1x dx= 0.1
[302 - 202]= 0.05[900 - 400] = 0.05 × 500 = 25 jouleNow, initial kinitic energy
10 × 100 = 500 jouleCreate a free account to view solution
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