Question

A body of mass 10 kg is moving with a velocity of 10ms-1. Find the force required to stop it in 2 seconds.

Answer 1

Answer:

Force = 50N in the opposite direction of the body

Explanation:

Mass = 10kg

U = 10m/s

V= 0

Time = 2s

Force = Mass * Acceleration

Now, a=

v = u + at

0 = 10 + a*2

-10 = 2a

-5 = a

now force = M*a

= 10* -5

= -50N or 50N in the opposite direction of the body

Answer 2

Force and acceleration

Force is defined as the product of mass and acceleration of the body. It is represented as F. SI units of mass and acceleration are kilogram and meter-per second respectively. Hence the SI unit of force is kilo-meter per second. This is also called Newton.

Here we are given with the mass of body, initial velocity, final velocity and final time taken by the body. With this information we've been asked to find out the force.

Given that, A body of mass 10 kg, initial velocity 10m/s, final velocity 0m/s and final time taken 2 seconds.

To find the force applied by the body, we will need acceleration value which is not given in the question, so first we need to find out the acceleration. We can find the acceleration by using first equation of motion.

The first equation of motion deals with final velocity, initial velocity, acceleration and final time taken.

In mathematical term it would be like this;

$\implies v = u + at$

[Here, v is the final velocity, u is initial velocity, a is the acceleration and t is the time taken.]

By using the formula and substituting the available values in it, we get:

$\implies 0 = 10 + a \times 2 \\ \\ \implies 0 = 10 + 2a \\ \\ \implies 0 - 10 = 2a \\ \\ \implies - 10 = 2a \\ \\ \implies a = \cancel{\dfrac{ - 10}{2} } \\ \\ \implies \boxed{a = - 5}$

Now, We got the value of acceleration, now we can easily find out the force applied by the body, By using second law of Newtown.

The product of mass and acceleration is equal to the force. In mathematical term it would be like this;

$\implies F = ma$

[Here, F is the force, m is the mass of body and a is the acceleration produced by the body.]

By using the formula and substituting the available values in it, we get:

$\implies F = 10 \times (-5) \\ \\ \implies \boxed{F = -50 \: N}$

Therefore, the force required to stop it in 2 seconds will be -50 N.