You are called as an expert witness in a trial for a traffic violation. The facts are these: A driver slammed on his brakes and came to a stop with constant acceleration. Measurements of his tires and the skid marks on the pavement indicate that he locked his car’s wheels, the car traveled 192 ft before stopping, and the coefficient of kinetic friction between the road and his tires was 0.750. He was charged with speeding in a 45-mi/h zone but pleads innocent. What is your conclusion: guilty or innocent? How fast was he going when he hit his brakes?

And we can convert this speed to mi/h and we got:

Explanation:

For this case we know the following info given:

represent the distance

represent the final velocity

represent the kinetic friction coefficient

the maximum velocity

For this case from the second Law of newton we have that:

Assuming that we have just the friction acting we have:

And replacing we have:

From kinematics we know that:

And solving for the initial velocity we got:

And we can convert this speed to mi/h and we got:

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form