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pav-90 [236]
1 year ago
13

calculate the work done in kilo joules in lifting a mass of 20kg at steady velocity through a vertical height of 20m

Physics
1 answer:
bulgar [2K]1 year ago
5 0

Answer:

\huge\boxed{\sf Work\ done = 4 kJ}

Explanation:

Since work done is in the form of potential energy, we will use the formula of potential energy here.

We know that,

<h3>P.E. = mgh </h3>

Where,

m = mass = 20 kg

g = acceleration due to gravity = 10 m/s²

h = vertical height = 20 m

So,

<h3>Work done = mgh</h3>

Work done = (20)(10)(20)

Work done = 4000 joules

Work done = 4 kJ

\rule[225]{225}{2}

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Answer:

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Explanation:

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2 years ago
A high-jump athlete leaves the ground, lifting her center of mass 1.8 m and crossing the bar with a horizontal velocity of 1.4 m
Romashka [77]

Answer:

The minimum speed when she leave the ground is 6.10 m/s.

Explanation:

Given that,

Horizontal velocity = 1.4 m/s

Height = 1.8 m

We need to calculate the minimum speed must she leave the ground

Using conservation of energy

K.E+P.E=P.E+K.E

\dfrac{1}{2}mv_{1}^2+0=mgh+\dfrac{1}{2}mv_{2}^2

\dfrac{v_{1}^2}{2}=gh+\dfrac{v_{2}^2}{2}

Put the value into the formula

\dfrac{v_{1}^2}{2}=9.8\times1.8+\dfrac{(1.4)^2}{2}

\dfrac{v_{1}^2}{2}=18.62

v_{1}=\sqrt{2\times18.62}

v_{1}=6.10\ m/s

Hence, The minimum speed when she leave the ground is 6.10 m/s.

6 0
3 years ago
You are designing a new home for a cold climate. You want one room in the house to be warmed by the Sun's energy. Which material
solniwko [45]

Answer:

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Explanation:

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8 0
2 years ago
Read 2 more answers
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aleksandr82 [10.1K]

Answer:

A. -30 N

Explanation:

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5 0
2 years ago
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Calculate the mass of a liquid with a density of 2.5 g/ml and a volume of 15ml
Nana76 [90]
Using the density equation and clearing mass:

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3 0
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