Physics, 14.11.2019 18:31 kenneth0125

it takes 6.0 seconds for a pulley system to lift a crate weighing 300 n to a height of 5.0 meters. how much power is required to lift the crate?

360 w

250 w

10 w

0.1 w

Answers: 2

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Answers

Considering the definition of work and power, the correct answer is the second option: the power is required to lift the crate is 250 W.

Power

Power is defined as how fast work is done. That is, power is the amount of work done per unit of time:

$Power=\frac{work}{time}$

P is the power developed by the force that performs the work and its unit of measurement in the International System is Watts (W).

The unit of measurement of work in the International System is the Joule (J). The time during which the work is developed has the unit of measurement in the International System of seconds (s).

Work

On the other side, work is defined as the force that is applied on a body to move it from one point to another.

When a net force is applied to the body or a system and this produces displacement, then that force is said to perform mechanical work. This work can be positive if the system gains energy or negative if the system loses energy.

The work is equal to the product of the force by the distance and by the cosine of the angle that exists between the direction of the force and the direction that travels the point or the object that moves.

This case

In this case, the angle between the force and the displacement is 0 degrees. This is because the force and the displacement are in the same direction and sense, in the horizontal direction. So the cosine of 0 degrees will have a value of 1. Then work is equal to:

Work= force× distance

Being the force 300 N and the distance 5 meters, the work can be calculated as:

Work= 300 N× 5 meters

Solving:

Work= 1,500 J

Finally, being the time 6 seconds, the power can be calculated as:

$Power=\frac{1,500 J}{6 s}$

Solving:

Power= 250 W

In summary, the correct answer is the second option: the power is required to lift the crate is 250 W.

Learn more about power and work:

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Answer from: kaylaamberd

The answer is 250W

Explanation:

Power(W) = work done(Nm)/time(s)

work done = force × distance

= 300 × 5

= 1500Nm

Power = 1500/6

= 250W

Answer from: Quest

v=ir = 3x15 =45 v

Answer from: Quest

it doesn't. it was imagined up in the middle ages.

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it takes 6.0 seconds for a pulley system to lift a crate weighing 300 n to a height of 5.0 meters. h...