A car moving at 8 m/s crashes into a barrier and stops in 0.050 s. There is a 19-kg child in the car. Assume that the child's velocity is changed by the same amount as that of the car, and in the same time period. (a) What is the impulse needed to stop the child in N*s?(b) What is the average force on the child in N? (c) What is the approximate mass of an object in kg whose weight equals the force in part (b)?

(a).The impulse needed to stop the child is 152 kg m/s.

(b). The average force on the child is 3040 N.

(c). The approximate mass of an object is 310.2 kg

Explanation:

Given that,

Speed of car = 8 m/s

Mass of child = 19 kg

Time = 0.050 s

(a). We need to calculate the impulse needed to stop the child

Using formula of impulse

Negative sign shows the net force is in negative direction.

The impulse needed to stop the child is 152 kg m/s.

(b). We need to calculate the average force on the child

Using formula of impulse

Put the value into the formula

Negative sign shows the opposite direction of the force

The average force on the child is 3040 N.

(c). We need to calculate the approximate mass of an object

Using formula of force

Put the value into the formula

The approximate mass of an object is 310.2 kg

Hence, (a).The impulse needed to stop the child is 152 kg m/s.

(b). The average force on the child is 3040 N.

(c). The approximate mass of an object is 310.2 kg

e/c, where e is its total energy