Answer:
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:
[tex]v_f=v_o+at[/tex]
Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
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:
[tex]\displaystyle a=\frac{0-20.4}{7.4}[/tex]
[tex]a=-2.757\ m/s^2[/tex]
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:
[tex]F = 1,126\ kg * 2.757\ m/s^2[/tex]
F= 3,104 N
The force required is 3,104 N
