A car accelerates uniformly from 5 m/s to 10 m/s in 5 s. Class 9

A car accelerates uniformly from 5 m/s to 10 m/s in 5 s. Class 9

Question 1.

A car accelerates uniformly from 5 m/s to 10 m/s in 5 s. What is the

i) acceleration and

ii) distance covered by carin that time Class 9

Answer:

Initial velocity, u = 5 m/s, Final velocity, v = 10m/s and time t = 5 s

v = u + at

10 = 5 + 5a

a = 1 m/s²

s = ut + 1/2 at²

= 5 × 5 + 1/2 × 1 × (5)² = 37.5 m

Question 2.

The brakes applied to car produce an acceleration of 6 m/s² in the opposite direction to motion. If car takes 2 s to stop after the application of brakes, calculate the distance it travels during this time Class 9

Answer:

Final velocity, v = 0 m/s and time t = 2 s [a = 2 m/s² as in opposite direction]

v = u + at

0 = u + (-6) × 2

u = 12 m/s

s = ut + 1/2 at²

= 12 × 2 + 1/2 × (-6) × (2)² = 24 - 12 = 12m