Question

A force with a magnitude of 400 N is used to stop an object with a mass of 59 kg moving at a velocity of 125 m/s. How long will it take to bring the object to rest?

PLEASE HELP ASAP

Answer 1

t = 18.43[s]

Step-by-step explanation:

This problem can be divided into two parts, in the first part we will use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.

`F=m*a`

where:

F = force = 400 [N]

m = mass = 59[kg]

a = acceleration [m/s²]

Now replacing:

`400=59*a\\a=400/59\\a=6.78[m/s^(2) ]`

Now we must use the following equation of kinematics.

`v_(f)=v_(o)-a*t`

where:

Vf = final velocity = 0 (to bring the object to rest)

Vo = initial velocity = 125 [m/s]

a = acceleration = 6.78 [m/s²]

t = time [a]

Now replacing:

`0=125-6.78*t\\6.78*t=125\\t=18.43[s]`