You apply the brakes of your car abruptly and your book starts sliding off the front seat. three observers explain thisdifferently. observer a says that the book continued moving and the car accelerated from underneath it. observer b saysthat the car pushed forward on the book observer c says that she must be in a noninertial reference frame because thebook started moving without any extra objects interacting with it. which of the observers is correct? (a) a (b) b (c) c(d) a and c (e) all of the observers

The correct observations are d) A and C

Explanation:

Let's schematically solve the exercise before analyzing the observation.

When the brakes are applied, there is a force in the opposite direction of the speed that decreases its value,

The book is subject to Newton's first and tends to follow its movement without changing the speed, there is also a force of friction directed backwards between the seat and the book, but it is not enough to stop it,

Observer

A) true. The book according to Newton's first law continued to move, but the car began to stop below.

B) False. The book is the one that moves forward

.c) True, Observer C is in the car, then he has an acceleration and sees that the book moves without any more applied forces.

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

see earlier answer