Question

A constant force of 10 N is exerted on a body of mass 20 kg initially moving with a speed of 20 m/s. How long will it take for the body to come to a stop?

a) 2 seconds
b) 4 seconds
c) 8 seconds
d) 10 seconds

Answer 1

The body will take 2 seconds to come to a stop.

Step-by-step explanation:

To find the time it takes for the body to come to a stop, we can use the equation:

Final velocity = Initial velocity + (acceleration × time)

In this case, the final velocity is 0 m/s (since the body comes to a stop), the initial velocity is 20 m/s, and the acceleration can be calculated using Newton's second law (F = ma).

So, the equation becomes:

0 = 20 + (10 × time)

Solving for time, we get:

time = -20 / 10 = -2 s

Since time cannot be negative in this context, we take the positive value:

time = 2 seconds