Question

Calculate the force required to impart to a car of velocity of 30 m/s in 10 s starting from rest. The mass of the car is 15000 kg

Answer 1

$\huge{\underline{\underline{Answer\::-}}}$

$\underline{\underline{Given\::-}}$

• Mass of car = 15000 Kg

• Final velocity of car = 30 m/s

• Initial velocity of car = 0 m/s

• Time taken for this = 10 seconds

$\underline{\underline{Solution\::-}}$

♦ Before solving we should know :-

• What is Force ?

>> Force is the Push or Pull , which can change state or direction of motion .

• How to find out Force ?

>> Force applied = Mass of object × acceleration

♦ Now to find out the Force we should find out acceleration of the car .

>> Acceleration

= $\bold{\dfrac{Final\: velocity - Initial\: Velocity}{Time\: taken}}$

=> Acceleration = $\bold{\dfrac{30 - 0 }{10 }}$

=> Acceleration = $\bold{\dfrac{30 }{10 }}$

=> Acceleration = $\bold{3 \frac{m}{s^2}}$

♦ Now we will find out the force

Force applied = Mass × Acceleration

F = 15000 × 3

F = 45000 N

So force required to impart the car = 45000 N

Answer 2

Car is Starting From rest

Intial Velocity (u)=0 m/s

Final Velocity (v)=30 m/s

Time(t)=10s

Accerlation=a

Using Equation of Motion

v=u+at

30=0+a×10

30=10a

a=30/10

a=3 m/s²

Accerlation of Car=3 m/s²

We Know

Mass=15000 kg

Force=Mass×Accerlation

Force=15000×3

Force=45000 N

$\implies$ SI unit of Force is Newton (N)

$\implies$ Accerlation is defined as rate of changing Velocity of a Object.

Like here Accerlation is 3m/s² means Every 1 second there is increase of Velocity 3m/s.

$\boxed{\mathbf{\huge{Force=45,000\:N}}}$