Question

A car of mass 1000kg and a bus of mass 5000kg are moving with the same velocity of 36 km/h. Find the forces to stop both the car and the bus in 5 seconds. Please write original answers and not TRASH. Your help is appreciated.

Answer 1

Answer:

• Force required to stop the bus = -2000N

• Force required to stop the bus,= -10000 N

Explanation:

Given :

• Mass of the car,$\rm{m_1}$ = 1000kg

• Mass of the bus,$\rm{m_2}$ = 5000kg

• Initial value of both car and bus,u = 36km/h =36*1000/60*60=10m/s

To Find

• Force to stop both the car and the bus.

Solution :

To find force,first we have to find acceleration.

So,

$\sf{}v=u+at$

$\Rightarrow \sf{}0=10+a\times5$

$\Rightarrow \sf{}-10=5a$

$\Rightarrow \sf{}-\dfrac{10}{5}=a$

$\Rightarrow \sf{}2m/s^2$

Therefore,

∴ Force required to stop both a car :-

$\sf{}F_1=m_1a$

$\Rightarrow \sf{}F_1=1000\times -2$

$\Rightarrow \sf{}F_1=-2000$

∴ Force required to stop both a bus :-

$\sf{}F_2=m_2a$

$\Rightarrow \sf{}F_2=5000\times -2$

$\Rightarrow \sf{}F_1=-10000N$

Negative sign of the force shows that the force is applied in the opposite direction.Such a force is known as retarding force.