Question

A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms^-1. The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is ______.

[use g = 9.8 ms^-2]

Options

• 4.9 m

• 9.8 m

• 12.5 m

• 19.6 m

Answer 1

A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms^-1. The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is 9.8 m.

Explanation:

a = `"f"/"m"=(mu"mg")/"m"=mu"g"`

So, S = `mu^2/(2"a")`      [∵ v = 0]

S = `9.8^2/(2xxmu"g")`

= `9.8^2/(2xx0.5xx9.8)` 

= 9.8 m