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A 1165 kg car traveling at 55 km/h is brought to a stop while skidding 38 m. Calculate the work done on the car by the friction forces.

A 1165 kg car traveling at 55 kmh is brought to a stop while skidding 38 m Calculate the work done on the car by the friction forces class=

Respuesta :

The work done is [tex]-1.36\cdot 10^5 J[/tex]

Explanation:

According to the work-energy theorem, the work done by external forces on the car is equal to the change in kinetic energy of the car. Therefore, we have:

[tex]W=\Delta K\\W = \frac{1}{2}mv^2-\frac{1}{2}mu^2[/tex]

where

W is the work done by the external forces

m is the mass of the car

v is its final velocity

u is its initial velocity

In this problem, we have:

m = 1165 kg

[tex]u=55 km/h =15.3 m/s[/tex]

v = 0 (the car comes to a stop)

Solving for W, we  find the work done by the frictional forces:

[tex]W=\frac{m(v^2-u^2)}{2}=\frac{(1165)(0-15.3^2)}{2}=-1.36\cdot 10^5 J[/tex]

Where the negative sign indicates that the direction of the force is opposite to the direction of motion of the car.

Learn more about work:

brainly.com/question/6763771

brainly.com/question/6443626

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