Question

q.1 A block is released from rest from a height h = 5 m. After traveling through the smooth curved surface it moves on the rough horizontal surface through a length l= 8 m and climb onto the other smooth curved surface through a height h. If $\mu$ = 0.5, find h.

• A. 2 m
• B. 3 m
• C. 1 m
• D. zero

Answer 1

The correct option is C 1 m

Given,

Coefficient of friction $\mu =0.5$

Length of track, $L=8m$

Initial height, $h=5m$

Conservation of Energy

Initial Potential Energy = Final Potential + Work done by friction

$mg{h}_1=mgh+\mu mgL$

$h=\frac{mg{h}_1-\mu mgL}{mg}=h_1-\mu L$

$h=5-0.5\times 8=1m$

Block climb to the other smooth curved surface through a height $1m$.