A2.80 kg mass is dropped from a height of 4.50 m. find its kinetic energy(ke) when it is 1.50 m above the ground?

82.32 J

Explanation:

Given:

Mass,

Initial height,

Final height,

As the mass is dropped, its initial velocity is 0 m/s.

So, initial kinetic energy is also 0 J.

Now, according to conservation of energy,

Increase in Kinetic energy is equal to the decrease in potential energy.

Here, Decrease in potential energy is given as,

Δ

Now, increase in kinetic energy is equal to the kinetic energy at height as the initial kinetic is 0.

∴ Kinetic energy at height 1.50 m above ground is given as the decrease in potential energy.

So, Kinetic energy = Decrease in potential energy =

Kinetic energy at height 1.50 m above ground is .

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 components of a vector are the parts of the vectors that are to each other.

b perpendicular