Question

A box of mass 20kg is pushed along a rough floor with a velocity 2m/s and then let go. The box moves 5m on the floor before coming to rest. What must be the frictional force acting on the box? plz give me the correct answer.....with proper STEPS......

Answer 1

${\huge{\underline{\red{Answer:}}}}$

${\huge{f}}$= 8 N in opposite direction

${\huge{\underline{\blue{Given:}}}}$

Mass of the box (m) = 20 kg

Initial Velocity (u) = 2 m/s

Final velocity (v) = 0 m/s

Distance travelled (S) = 5 m

${\huge{\underline{\pink{To Find:}}}}$

Fictional force acting on the box

${\huge{\underline{\orange{Formulas:}}}}$

v² - u² = 2as ; F = ma

${\huge{\underline{\green{Solution:}}}}$

v² - u² = 2as

(0)² - (2)² = 2(a)(5)

a = -4/10 = -0.4 m/s²

___________________

F = ma = 20 × -0.4

= -8N in same direction

= 8N in opposite direction