Question

Figure shows the frictional force versus displacement for a particle in motion. The
loss of kinetic energy (work done against friction) in travelling over s = 0 to s = 20 m will
be

Answer 1

Answer:

(c) is the correct answer

Explanation:

Loss in kinetic energy is equal to the work done by the frictional force=∫ f.dx

Thus work done is equal to the area under the given curve. Therefore area is given by

=(1/2x(5+15)x5 )+(5+15)+(1/2x(15+10)x10)=250J

Answer 2

Answer:

Explanation:Loss in kinetic energy is equal to the work done by the frictional force=∫

f

​

.

dx

Thus work done is equal to the area under the given curve. Therefore area is given by,

=(

2

1

​

×(5+15)×5)+(15×5)+(

2

1

​

×(15+10))×10)=250J