Question

A car starts from rest rolls down with
constant acceleration. It travels a distance of
400m in 20 sec. Find the acceleration
produced and force acting on it, if its mass
of the car is 7000 kg.​

Answer 1

Answer:

2m/s^2,14000N

Explanation:

the above given is the answer for the question

Answer 2

Answer:

Given :

Mass of the bus = 7000 kg

Time = 4 sec

Velocity of the bus = 36 km/hr

To Find :

The Force applied to stop the bus

Solution :

using first equation of motion , v = u + at

Here ,

v is final velocity

u is initial velocity

a is acceleration

t is time

We have ,

v = 0 {since it comes to rest}

u = 36 km/hr = 36(5/18) m/s = 10 m/s

t = 4 sec

Mass = 7000 kg

Substituting the values ;

➙ 0 = 10 + (F/m)(4) { ∵ a = F/m}

➙ 0 = 10 + (F/7000)(4)

➙ 0 = 10 + (4F/7000)

➙ 0 = (70000 + 4F)/7000

➙ 0 = 70000 + 4F

➙ -70000 = 4F

➙ F = -70000/4

➙ F = -17500 N \begin{gathered}\\\end{gathered}

Hence ,

The Force that should be applied to bring the bus to rest is -17,500 N