How long will it take a 2.93 hp motor to lift a 250 kg beam directly upward at constant velocity from the ground to a height of 45.0 m? assume frictional forces are negligible. (1 hp = 746 w)how long will it take a 2.93 hp motor to lift a 250 kg beam directly upward at constant velocity from the ground to a height of 45.0 m? assume frictional forces are negligible. (1 hp = 746 w)50.4 s5.26 × 104 s3.76 × 104 s95.8 s

50.4 s

Explanation:

The energy expended by the motor, must be equal to the work done by it, which is just equal to the change in the gravitational potential energy of the beam, as we are told that the beam is being lifted directly upward at constant speed (so, the applied force is equal and opposite at any time to the gravity force on the beam) , as follows:

W = m*g*h = 250 kg. * 9.8 m/s²* 45.0 m = 110,250 J

Now, as Power is just Energy / Time, we need just to solve for time this equation.

But, prior to be able to solve this equation, we need that our units be consistent.

As we are given the motor power in HP, we need to convert this unit to Joules/seg, as follows:

1 HP = 746 W  

2.93 HP = 2.93 HP * (746W/1HP) = 2,186 J/s

Solving the Power equation for t:

t = W/P = 110,250 J / 2,186 J/s = 50.4 s  

c.is a substance that requires a small amount of energy per gram to raise its temperature; has strong cohesive forces between molecules.

explanation:

a colorless, transparent, odorless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force