Question

A car attains a velocity of 54km/h within 5 sec from an initial velocity of 18km/h. Calculate its acceleration and displacement​

Answer 1

Explanation:

Given :

• Final velocity ( v ) = 54km/h

converting u in m/sec = 54×5/18

= 15m/sec

• Initial velocity ( u ) = 18km/h

converting v in m /sec² = 18× 5/18

= 5m/sec

• Time = 5sec

To Find :

• Acceleration ( a )
• Displacement ( s )

Required formula for finding "a" and "s" :

• for acceleration (a) ==>

first equation of motion

=> v = u+at

• for Displacement (s) ==>

3rd equation of motion

==> 2as = v²-u²

Solution :

• Acceleration =

using 1st equation of motion

=> v = u+at

=> 15 = 5 + 5a

=> 5a = 15-5 = 10

=> a = 10/5

=> a = 2

so, the acceleration of Car => 2m/sec²

• Displacement =

using 3rd equation of motion

=> 2as = v²-u²

=> 2×2×s = 15² - 5²

=> 4s = 225 - 25 = 200

=> s = 200/4

=> s = 50

so, the displacement = 50m