Ahockey puck is given an initial speed of 5.0 m/s. if the coefficient of kinetic friction between the puck and the ice is 0.05, how far does the puck slide before coming to rest? solve this problem using conservation of energy.

d = 25.51 m

Explanation:

the law of the conservation of energy says that:

where is the inicial energy, is the final energy and is the work of the friction.

so:

=

where M is the mass and V the velocity.

also,

where is the coefficient of kinetic frictio, N is the normal force and d is the distance.

therefore:

also, N is equal to the mass of the hockey puck multiplicated by the gravity.

replacing:

canceling the m:

solving for d:

d = 25.51 m

1 the 4 is sig

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.