Question

A force 4000 N accelerates a car of mass 800 kg from rest to 20 m/s. How far does the car travel while the force is acting?

Answer 1

Given :-

• Force ( F ) acting on the car is 4000 N  
• Mass ( m ) of the car is 800 kg  
• Initial velocity ( u ) of the car is 0 m/s  
• Final velocity ( v ) of the car is 20 m/s

To Find :-

• How far does the car travel while the force acting ( s = distance )

Solution :-

~Here, we’re given the mass of the car , force acting on it and it’s final and initial velocity and we need to find the distance travelled by the car when the force was acting on it. Firstly we’ll find acceleration of the car by putting the values in the formula of finding force and then find the distance by the third equation of motion.

_____________

As we know that ,

★ F = m × a

Where,

• F is force
• m is mass  
• a is acceleration

★ v ²– u² = 2as

Where,

• v is final velocity  
• u is initial velocity  
• a is acceleration  
• s is distance  

_____________

Finding the acceleration :-

⟶  F = m × a  

⟶  4000 = 800 × a  

⟶  a = 4000/800  

⟶  a = 5 m/s²

Finding the distance :-

⟶  v² – u² = 2as  

⟶  ( 20 )² – ( 0 )² = 2 × 5  × s  

⟶  400 – 0 = 10s  

⟶  400 = 10s  

⟶ s = 400/10  

⟶ s = 40 m  

_____________

Hence,  

• The car travelled a distance of 40 m when the force was acting on it.