Question

Feeling a bit better about not getting the Nobel Prize, Meitner drove home from the rink. If her 1500kg car accelerated from rest to a speed of 20 m/s in 10 seconds, what was the force exerted by the car engine?

Answer 1

The force exerted by the car engine was 3000 N

Step-by-step explanation:

Mechanical Force

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

`F=m.a`

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:

`v_f=v_o+a.t`

Where:

vf is the final speed

vo is the initial speed

a is the acceleration

t is the time

The question describes how Meitner drove home taking her car from rest to a speed of 20 m/s in 10 seconds. This provides us the following data:

vf=20 m/s, v0=0 (rest), t = 10 seconds.

From the kinematics equation, we can solve for a:

`\displaystyle a=(v_f-v_o)/(t)`

`\displaystyle a=(20\ m/s-0)/(10\ s)=2\ m/s^2`

The force exerted by the car engine was:

`F=1500\ kg\cdot 2\ m/s^2`

`F=3000\ N`

The force exerted by the car engine was 3000 N