A child applies a force F parallel to the x -axis to a 10.0-kg sled moving on th

Question

A child applies a force F  parallel to the x-axis to a 10.0-kg sled moving on the frozen surface of a small pond. As the child controls the speed of the sled, the x-component of the force she applies varies with the x-coordinate of the sled as shown in figure (Figure 1). Suppose the sled is initially at rest at x=0. You can ignore friction between the sled and the surface of the pond.

a. Use the work-energy theorem to find the speed of the sled at 6.0 m .

Explanation / Answer

From the graph above Work done can be calculated by area under graph.

At 8m work done = 1/2×8×10=40 joule

From Work energy theorem

work done= change in K.E

40= 1/2mv2 -0(As intial K.E is zero)

v=(80/10)1/2

V=2.82m/s

Now at 12 m Work done =1/2×10×4=20 Joule

Work done = change in K.E

20=1/2×10×(v2-2.822)

v=3.46m/sec

NOTE: Velocity is calculated at 8m instead of 6m as it seems a typing error because it is not possible to calculate velocity at 6m without approximation from graph

Please give a like if satisfied and if any doubt mention in comment I will clear it.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.