Question

A woman is wearing her seat belt, while driving at 60 km/h. She finds it necessary to slam on her brakes and slows uniformly to a stop in 1.6 s. What is the average acceleration experienced by her? (a) -10.4 m/s? (b) 10.4 m/s2 (c) 1.04 m/s? (d) - 1.04 m/s? 2. 2.​

Answer 1

Answer

Your answer will be 10.4m/s sq.

Answer 2

Given: initial speed = 60 km/h

           Time = 1.6 seconds

To find: average acceleration  experienced

Solution:

Converting 60 km/h into m/s

= 60 ×1000/60×60 = 100/6 m/s

Therefore, the initial velocity = 100/6 m/s

Since the body stops therefore, the final velocity = 0

Acceleration = (final velocity - initial velocity)/time

                     = (0-100/6)/1.6

                    = -10.4 m/s²

Therefore, the acceleration experienced by the women will be 10.4 m/s² and the correct option is (a).

• The negative sign implies that the velocity of the car decreases with time.

• Acceleration is the rate of change of velocity, and its magnitude is equal to the change in velocity divided by the time taken to cause that change in velocity.
• It is a vector quantity and therefore has both magnitudes as well as direction. Its direction is along with the movement of the body.