Question

One day while moving boxes you get tired and decide to use a rocket instead. You attach a small rocket of negligible mass to a 8.48 kg box. When you turn the rocket on, it provides a constant thrust of 192 N, and the sbox begins sliding across the pavement. If the magnitude of acceleration of the box is 12.8 m/s², what is the coefficient of kinetic friction between the soapbox and pavement?

1.00
3.62
3.82
1.31

Answer 1

Gravitational acceleration = g = 9.81 m/s²

Mass of the box = m = 8.48 kg

Thrust force provided by the rocket = F = 192 N

Acceleration of the box = a = 12.8 m/s²

Normal force on the box from the pavement = N

Coefficient of kinetic friction between the box and the pavement =

Friction force on the box = f = N

From the free body diagram,

N = mg

f = mg

ma = F - f

ma = F - mg

(8.48)(12.8) = 192 - (8.48)(9.81)

= 1.00

Coefficient of kinetic friction between the box and the pavement = 1.00