A box of mass 84 kg is at rest on a horizontal frictionless surface. A constant horizontal force F then acts on the box and accelerates it to the right. It is observed that it takes the box 7.1 seconds to travel 85 meters. What is the magnitude of the force?

The magnitude of force is 571.2 N.

Explanation:

Given data :-

i) Mass of the box = 84 kg.

ii) Frictionless surface means  friction force is zero.

iii)The force ( F ) which act on box = m*a.  

iv) The time for which the box is in motion ( t ) = 5 seconds.

v) The distance traveled by box ( S ) = 85 meter.

Now to find magnitude of force we have to calculate the value of acceleration.

We know the equation of motion.

S = (u*t )+0.5 (a*t²)

85 = 0 + 0.5 * a *5²     ( u = initial velocity = 0 )

a = 6.8 m²/s.

∴ F = m*a = 84 * 6.8 = 571.2 N

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