Here you have to consider that at the beginning you have an amount of kinetic energy (K) that is dissipated because of the work done by friction forces (T). Since the car is stopped after the accident, all the energy has been dissipated. Thus, $K=T$ .

The definition of the kinetic energy is $K=1/2*m*v^2$ .

The work done by the friction forces is: $T=f*(m*g)*d$ . Where f is the friction coefficient, g is the gravity acceleration, m is the mass of the car and d is the skid marks longitude. Therefore,

$1.2*m*v^2=f*(m*g)*d$

Since m is in both sides it can be cancelled so it is not necessary to considered.

Then, the speed is determined by the following equation:

$v=\sqrt{2*f*g*d} =\sqrt{2*0.42*9.8m/s^2*88 m}=26.91 m/s$

4 0

3 years ago

Please help. I'll mark you brainliest. ((:

alexgriva [62]

I believe that if you shine a light in the front of a binocular, then the light would condense and be more pin-pointed while if you point it through the part where your eyes go the light would blow up. Either way, the light will be refracted once it travels through the lenses.

5 0

4 years ago

a water wave has a speed of 23.0 meters/second. if the waves frequency is 0.0680 hertz, what is the wavelength

USPshnik [31]

Answer:

Using the Fundamental Equation of Wave, we have:

Explanation:

7 0

3 years ago