Answer:
A, the energy an object has due to its motion.
Explanation:
Kinetic energy is the energy created by motion.
The amount of gravitational potential energy acquired by the rock is equal to:
where
m is the mass of the rock
g is the gravitational acceleration
is the increase in height of the rock
Substituting the data of the problem, we find
So, Natalie gave 220.7 J of energy to the rock.
The correct answer is A. 32.5
Mechanical advantage is the ratio of force that is input into a machine to the force output.
Mechanical advantage of a wheel and axle is calculated by dividing the radius of the wheel by that of the axle.
MA=R/r where R is the radius of the wheel and r is the radius of the axle.
Substituting for the values in the question gives:
MA=26cm/0.8cm
=32.5
Calculate velocity at halfway to the ground.
vfinal = root 2ad
v = root (2*9.81m/s^2*25)
v = 69.367175234 m/s
Kinetic energy = 1/2mv^2
Kinetic energy = 1/2 * (69.367175234 m/s^s^2
Ek = 2405.9025 Joules
Answer:
Lubrication is used to reduce friction. It is generally used for moving machine parts. The lubricants are the substances which are used to reduce the friction which acts between two surfaces in contact, between which relative motion can occur.
