Question

when a car driver traveling at a speed of 10 meter per second applies break and bring the car to rest in 20 seconds then the acceleration will be​

Answer 1

CORRECT QUESTION :-

★ A car driver travelling car at a speed of 10 m/s applies break and bring the car to rest in 20 seconds the the Acceleration will be.

GIVEN :-

• Initial velocity , u = 10 m/s.
• Final velocity , v = 0 m/s. [Breakers are applied]
• Time , t = 20 seconds.

TO FIND :-

• The Acceleration , a.

SOLUTION :-

→ Change in velocity = Final velocity - Initial velocity.

→ v - u

→ 0 m/s - 10 m/s

→ -10 m/s.

Now as we know that,

→ Acceleration = Change in velocity/time

→ a = v - u/t

→ a = -10/20

→ a = -1/2 m/s².

Note :- The negative sign (- ve) indicates retardation of Acceleration.

Hence the acceleration of car will be (-1/2) m/s².

Answer 2

Explanation:

Given:

Initial velocity, u = 10 m/s

Final velocity,,v = 0 m/s

Time taken = 20 second

To be calculated:

Calculate the retardation ( negative acceleration) ?

Formula used:

Acceleration = v - u / t

Solution:

We know that,

Acceleration = v - u / t

Substituting the values in the above formula, we get

Acceleration = 0 - 10 / 20

= -10 / 20

= -1 / 2

= -0.5 m/s²

Thus, the acceleration of the car is - 0.5 m/s². it is negative in sign ,but the negative acceleration is known as retardation.