FrictionHard
Question
A block of mass 2 kg is given a push horizontally and then the block starts sliding over a horizontal plane. The figure shows the velocity-time graph of the motion. The co-efficient of sliding friction between the plane and the block is: (Take g = 10 m/s2)
Options
A.0.02
B.0.20
C.0.04
D.0.40
Solution
(B)
at t = 0 v = 8
and at t = 4 v = 0
v2 = u2 + 2as
on putting the value
0 = 64 − 2 × a × s ...(1)
but s is area of v-t graph
s = 1/2 × 4 × 8 = 16 ....(2)
by equation (1) and (2) 0 = 64 − 2 × a × 16
a = 2
but a = μg = 2
So, μ = 2/10 = 0.20
at t = 0 v = 8
and at t = 4 v = 0
v2 = u2 + 2as
on putting the value
0 = 64 − 2 × a × s ...(1)
but s is area of v-t graph
s = 1/2 × 4 × 8 = 16 ....(2)
by equation (1) and (2) 0 = 64 − 2 × a × 16
a = 2
but a = μg = 2
So, μ = 2/10 = 0.20
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