Question

A car achieves a speed of 40m/s by undergoing uniform acceleration of 5m/s^2 in 3s. Find the initial speed of the car.

Answer 1

Answer :

• Initial speed of the car is 25m/s

Given :

• A car achives a speed of 40m/s by undergoing uniform acceleration of 5m/s² in 3s

To find :

• Initial speed of the car

Solution :

Given,

• Final speed (v) = 40m/s
• Acceleration (a) = 5m/s²
• Time = (t) = 3s
• Initial speed(u) = ?

As we know that,

• v = u + at

Where,

• v is final speed
• u is Initial speed
• a is acceleration
• t is time

》v = u + at

》40 = u + 5(3)

》40 = u + 15

》u = 40 - 15

》u = 25

Hence , Initial speed of the car is 25m/s

Verification :

》40 = u + 5(3)

》40 = 25 + 5(3)

》40 = 25 + 15

》40 = 40

Hence , Verified.

Answer 2

߷︎ Given :-

Final speed ( v ) = 40 m/s

Initial speed ( u ) = ?

Acceleration ( a ) = 5 m/s²

Time ( t ) = 3 sec

߷︎ To find :-

• Find the initial speed of the car.

$\purple{❍:}\underline{ \sf \: Formula \: used} :-$

$\: \: \: \: \: \: \: \: : \: \longmapsto \rm v = u + at$

߷︎ Solution :-

40 = u + 5 (3)

40 = u + 15

u = 40 - 15 = 25 m/s

Initial speed of a car is 25 m/s.