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3 years ago

For the PE formula, why is the height required for calculations? Why do we need to know the height in order to determine PE? *

Physics

1 answer:

Fudgin [204]3 years ago

5 0

Answer:

Answer in Explanation

Explanation:

Whenever we talk about the gravitational potential energy, it means the energy stored in a body due to its position in the gravitational field. Now, we know that in the gravitational field the work is only done when the body moves vertically. If the body moves horizontally on the same surface in the Earth's Gravitational Field, then the work done on the body is considered to be zero. Hence, the work done or the energy stored in the object while in the gravitational field is only possible if it moves vertically. This vertical distance is referred to as height. <u>This is the main reason why we require height in the P.E formula and calculations.</u>

The derivation of this formula is as follows:

Work = Force * Displacement

For gravitational potential energy:

Work = P.E

Force = Weight = mg

Displacement = Vertical Displacement = Height = h

Therefore,

P.E = mgh

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A uniformly charged ring of radius 10.0 cm has a total charge of 71.0 μC. Find the electric field on the axis of the ring at the

oee [108]

Answer:

General Expression: E = kql/(l² + r²)^(3/2)

(a) 6.3 MN/C

(b) 22.8 MN/C

(d) 0.63 MN/C

Explanation:

The general expression for electric field along axis of a uniformly charged ring is:

where,

E = Electric Field Strength = ?

k = Coulomb's Constant = 9 x 10⁹ N.m²/C²

q = Total Charge = 71 μC = 71 x 10⁻⁶ C

L = Distance from center on axis

r = radius of ring = 10 cm = 0.1 m

(a)

L = 1 cm = 0.01 m

Therefore,

E = (9 x 10⁹ N.m²/C²)(71 x 10⁻⁶ C)(0.01 m)/[(0.01 m)² + (0.1 m)²]^(3/2)

E = (6390 N.m³/C)/(0.00101 m³)

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(b)

L = 5 cm = 0.05 m

Therefore,

E = (9 x 10⁹ N.m²/C²)(71 x 10⁻⁶ C)(0.05 m)/[(0.05 m)² + (0.1 m)²]^(3/2)

E = (31950 N.m³/C)/(0.00139 m³)

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(c)

L = 30 cm = 0.3 m

Therefore,

E = (9 x 10⁹ N.m²/C²)(71 x 10⁻⁶ C)(0.3 m)/[(0.3 m)² + (0.1 m)²]^(3/2)

E = (191700 N.m³/C)/(0.03162 m³)

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(d)

L = 100 cm = 1 m

Therefore,

E = (9 x 10⁹ N.m²/C²)(71 x 10⁻⁶ C)(1 m)/[(1 m)² + (0.1 m)²]^(3/2)

E = (639000 N.m³/C)/(1.015 m³)

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3 years ago

When might i travel at a low velocity but high acceleration?

SCORPION-xisa [38]

Maybe when you ice-skate 10 times per second around a 1-foot circle.

7 0

4 years ago

if a man travels 10m north in 4s, stops for 20s, then travels 20 meters east in 15s, what is the man's average velocity for the

arsen [322]

Answer:

The average velocity from 1 to 3 seconds is 20 m/s l. X/T = 0 m/1s = zero.

Explanation:

I hope that helped!

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3 years ago

A man on a road trip drives a car at different constant speeds over several legs of the trip. He drives for 55.0 min at 60.0 km/

KatRina [158]

Complete Question

A man on a road trip drives a car at different constant speeds over several legs of the trip. He drives for 55.0 min at 60.0 km/h, 18.0 min at 80.0 km/h, and 60.0 min at 60.0 km/h and spends

25.0 min eating lunch and buying gas

What is the total distance traveled over the entire trip (in km)

Answer:

The value is $D = 139.02 \ km$

Explanation:

From the question we are told that

For $t_1 = 55 min = \frac{55}{60} = 0.917 \ h$ the speed is $v_1 = 60 \ km/h$

For $t_2 = 18 min = \frac{18}{60} = 0.3 \ h$ the speed is $v_2 = 80 \ km/h$

For $t_3 = 60 min = \frac{60}{60} = 1 \ h$ the speed is $v_3 = 60\ km/h$

The time taken to have lunch is $t _l = 25 \ min = \frac{25}{60} = 0.42 \ h$

Generally the total distance traveled over the entire trip (in km) is mathematically represented as

$D = t_1 * v_1 + t_2 * v_2 + t_3 * v_3$

=> $D = 0.917 * 60 + 0.3 * 80 + 1 * 60$

=> $D = 55.02 + 24 + 60$

=> $D = 139.02 \ km$

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4 years ago

How much power is used by a washing machine if it does 7,200 joules of work in 3 minutes?

elixir [45]

So, the power that used by the washing machine is <u>400 Watt</u>.

<h3>Introduction</h3>

Hi ! Here, I will help you to calculate the power generated. <u>Power is work done per unit time</u>. If a person or machine can do a <u>large amount of work in the shortest possible time, it will produce or require a large amount of power</u>. The relationship between power, work, and time is expressed in the equation:

$\boxed{\sf{\bold{P = \frac{W}{t}}}}$