Question

A car driver barkes gently. Her car slows down from 23m/s to 11m/s in 20sec .what is it deceleration

Answer 1

Provided that:

• Initial velocity = 23 mps
• Final velocity = 11 mps
• Time = 20 sec

To calculate:

• The deceleration

Solution:

• The deceleration = -0.6 mps

Using concept:

• Either acceleration formula or first equation of motion.

Using formula:

• Acceleration formula:

• a = (v-u)/t

• First equation of motion:

• v = u + at

Where, a denotes acceleration, u denotes initial velocity, v denotes final velocity and t denotes time taken.

Required solution:

~ Let us solve this question!

By using acceleration formula...

»»» a = (v-u)/t

»»» a = (11-23)/20

»»» a = -12/20

»»» a = -6/10

»»» a = -0.6 mps sq.

»»» Acceleration = -0.6 mps sq.

»»» Deceleration = -0.6 mps sq.

By using first equation of motion...

»»» v = u + at

»»» 11 = 23 + a(20)

»»» 11 - 23 = 20a

»»» -12 = 20a

»»» a = -12/20

»»» a = -6/10

»»» a = -0.6 mps sq.

»»» Acceleration = -0.6 mps sq.

»»» Deceleration = -0.6 mps sq.