An object of mass 1 kg moving on a horizontal surface with initial velocity 8 m/s comes to rest after 10 s. If one wants to keep the object moving on the same surface with velocity 8 m/s the force required is

Question

An object of mass 1 kg moving on a horizontal surface with initial velocity 8 m/s comes to rest after 10 s. If one wants to keep the object moving on the same surface with velocity 8 m/s the force required is (A) 0.4 N (B) 0.8 N (C) 1.2 N (D) Zero

Tardigrade Admin · Accepted Answer

To find the frictional force offered by the ground

v = u + a t

v = 0

0 = 8 - μg (10)

μ = \frac{8}{100} = 0.08

To move the body with constant velocity on this surface, internal force applied should be equal to friction force,

F = μ m g

= (0.08) (1) (10) = 0.8 N

Q. An object of mass 1kg moving on a horizontal surface with initial velocity 8m/s comes to rest after 10s. If one wants to keep the object moving on the same surface with velocity 8m/s the force required is

0.4 N

0.8 N

1.2 N

Zero

To find the frictional force offered by the ground v=u+at v=0 0=8−μg(10) μ=1008​=0.08 To move the body with constant velocity on this surface, internal force applied should be equal to friction force, F=μmg =(0.08)(1)(10)=0.8N

Q. An object of mass $1 k g$ moving on a horizontal surface with initial velocity $8 m / s$ comes to rest after $10 s$ . If one wants to keep the object moving on the same surface with velocity $8 m / s$ the force required is

To find the frictional force offered by the ground
$v = u + a t$
$v = 0$
$0 = 8 - μg (10)$
$μ = \frac{8}{100} = 0.08$
To move the body with constant velocity on this surface, internal force applied should be equal to friction force, $F = μ m g$
$= (0.08) (1) (10) = 0.8 N$