Question

what was the magnitude of the average force exerted on your car during breathingWhat was the direction of the force exerted on your car during breakinghow far did you travel by breaking ?

Answer 1

Given:

The time duration for which the break was applied, t=1.00 s

The mass of the car, m=970 kg

The initial velocity of the car, u=16.0 m/s

The final velocity of teh car, v=9.50 m/s

To find:

Magnitude and direction of the average force exerted on the car.

Step-by-step explanation:

The acceleration of an object is the time rate of change of its velocity. Thus the acceleration of the car is given by,

`a=(v-u)/(t)`

On substituting the known values,

`\begin{gathered} a=(9.50-16.0)/(1.00) \\ =-6.5\text{ m/s}^2 \end{gathered}`

From Newton's second law of motion, the average force applied to the car is given by.

`F=ma`

On substituting the known values,

`\begin{gathered} F=970*-6.5 \\ =6305\text{ N} \end{gathered}`

The negative sign indicates the force in the opposite direction of motion of the car.

From the equation of motion, the distance travelled by car in this time is given by,

`d=ut+(1)/(2)at^2`

On substituting the known values,

`\begin{gathered} d=16.0*1.00+(1)/(2)*-6.5*1.00^2 \\ =12.75\text{ m} \end{gathered}`

Final answer:

The magnitude of the average force exerted on the car is 6305 N and it is directed in the direction opposite to the direction of motion of the car.

Thus the distance travelled after braking is 12.75 m