How much farther will a car skid if it locks its brakes at 60 mph as compared to a skid from 15 mph? assume the braking force that will eventually stop the cars is provided by the road and that it acts with equal magnitude in both situations. distance increases by a factor of 4 times 16 times impossible to tell because the mass of the car is not known impossible to tell because frictional force is not known

v₀ = initial velocity of the car before brakes are applied

v = final velocity of the car after it comes to a stop = 0 mph

d = stopping distance

a = acceleration caused due to braking force

Using the kinematics equation

v² = v²₀ - 2 a d

0² =  v²₀ - 2 a d

d = v²₀ /(2a)

Since the acceleration is same , the stopping distance is directly proportional to the square of the initial speed of car before brakes are applied

hence

d₁/d₂ = v²₀₁/v²₀₂

Given that : v₀₁ = 60 mph   and v₀₂ = 15 mph

inserting the values

d₁/d₂ = (60)²/(15)²

d₁ = 16 d₂

hence distance increases by a factor of 16 times.

the part of the wave he is travelling on is the crest

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.