QUESTION 7 How much force is required to bring a car of mass 1,126 kg, initially traveling at 20.4 m/s, to rest in 7.4 s?

The force required is 3,104 N

Explanation:

Force

According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:

F = ma

Where a is the acceleration of the object.

On the other hand, the equations of the Kinematics describe the motion of the object by the equation:

Where:

vf is the final speed

vo is the initial speed

a is the acceleration

t is the time

Solving for a:

We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:

The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:

F= 3,104 N

The force required is 3,104 N

sonar - device which is used to find the submit submarines, sankalp ship. sonar waves consists of a transmitter and detector which are installed in the observation centre on board of a ship. the ultrasonic waves are sent into the sea at high frequency about 1000 khz in all direction.

a.) is the correct answer.

explanation: