Question

A toy car initially moving with a uniform velocity of 18 km/ hr
comes to rest in 2 seconds. Find the retardation of the car in SI
units.

Answer 1

Answer:

2.5 m/s² is the retardation of the toy car.

Explanation:

We have,

• Initial velocity (u) = 18 Km/h
• Final velocity (v) = 0 Km/h
• Time taken (t) = 2 sec

To find,

• Retardation (r)

Solution,

Using the formula,

=> Acceleration = Change in velocity/Time taken

>> a = v - u/t

We have,

=> u = 18 × 5/18

• 5 m/s

=> v = 0 m/s

=> t = 2 sec

Substituting we get,

=> a = 0 - 5/2

=> a = -5/2

=> a = -2.5 m/s²

or r = 2.5 m/s²

∴ The retardation of the toy car is 2.5 m/s².