Ahockey puck is at rest on a flat surface. then one end of the surface is lifted gradually, forming an inclined plane of increasing slope. by measuring the angle of the slope at which the puck begins to slide, what quantity can be calculated?

the coefficient of kinetic friction between the puck and the surface

the mass of the puck

the volume of the puck

the coefficient of static friction between the puck and the surface

the coefficient of static friction between the puck and the surface

Explanation:

As per the FBD we can say that as we increase the angle of the inclination the component of force of gravity will counterbalance the friction force

At the condition of just equilibrium when it is just begin to slide then in that case we can say

so here for finding frictional force maximum value we can say

here for finding Normal force we can write force balance normal to the inclined plane

now from above equations

so angle depends on the coefficient of static friction

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.

the answer is 12 as i may remember

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