Question

A car increases its speed from 20 km/h to 50 km/h in 10 sec . what is acceleration ?​

Answer 1

Given:

• Initial velocity of Car, u = 20 km/h
• Final velocity of Car, v = 50 km/h
• Time taken for change in velocity, t = 10 sec

To find:

• Acceleration of Car, a =?

Formula required:

• First equation of motion

      v = u + a t

[ Where v is final velocity, u is initial velocity, a is acceleration and t is time taken ]

Solution:

Converting Initial and final velocities given in km/h into m/s

→ Initial velocity, u = 20 km/h

→ u = 20 × 5/18  m/s

→ u = 50/9  m/s

and

→ Final velocity, v = 50 m/s

→ v = 50 × 5/18  m/s

→ v = 125/9   m/s

Calculating acceleration of Car

Using first equation of motion

→ v = u + a t

→ 125/9 = ( 50/9 ) + a ( 10 )

→ 10 a = ( 125/9 ) - ( 50/9 )

→ 10 a = ( 125 - 50 ) / 9

→ 10 a = 75 / 9

→ a = 75 / 90

→ a = 25 / 30

→ a = 5 / 6

→ a = 0.834 m/s²

Therefore,

• Acceleration of the Car would be 0.834 m/s².

Answer 2

Answer:

83.33m/s^2

Explanation:

initial velocity =20 km/h

=(20*1000m)/60*60s

=50/9

final velocity =50km/h

=(50*1000m)/60*60s

=125/9

time taken =10s;a=?

a=(v-u)/t

=(125/9-50/9)/10

=(75*10)/9

=83.33m/s^2