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2 years ago

Gravitational potential energy (Eg) and kinetic energy (Ek)

Physics

2 answers:

STatiana [176]2 years ago

6 0

Answer:

hope it will help you

Explanation:

madreJ [45]2 years ago

4 0

Answer:

$\boxed {\boxed {\sf E_K= \ 5,040 \ J}}$

Explanation:

Kinetic energy is the energy an object possesses due to motion. It is calculated using the following formula:

$E_K= \frac{1}{2} mv^2$

The mass of the athlete is 70.0 kilograms. The velocity is 12 meters per second.

m= 70.0 kg
v= 12 m/s

Substitute the values into the formula.

$E_K= \frac{1}{2} (70.0 \ kg)(12 \ m/s)^2$

Solve the exponent.

(12 m/s)² = (12 m/s)(12 m/s) = 144 m²/s²

$E_K= \frac{1}{2} (70.0 \ kg)(144 \ m^2/s^2)$

Multiply the numbers together.

$E_K= \frac{1}{2} (10, 080 \ kg*m^2/s^2)$

$E_K= 5,040 \ kg*m^2/s^2$

Convert the units. 1 kilogram meter squared per second squared is equal to 1 Joule, so our answer is equal to 5,040 Joules.

$E_K= 5.040 \ J$

The athlete has <u>5,040 Joules</u> of kinetic energy.

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A toy rocket is fired vertically into the air from the ground at an initial velocity of 80 feet per second. Find the time it wil

miskamm [114]

Answer: 16.3 seconds

Explanation: Given that the

Initial velocity U = 80 ft/s

Let's first calculate the maximum height reached by using third equation of motion.

V^2 = U^2 - 2gH

Where V = final velocity and H = maximum height.

Since the toy is moving against the gravity, g will be negative.

At maximum height, V = 0

0 = 80^2 - 2 × 9.81 × H

6400 = 19.62H

H = 6400/19.62

H = 326.2

Let's us second equation of motion to find time.

H = Ut - 1/2gt^2

Let assume that the ball is dropped from the maximum height. Then,

U = 0. The equation will be reduced to

H = 1/2gt^2

326.2 = 1/2 × 9.81 × t^2

326.2 = 4.905t^2

t^2 = 326.2/4.905

t = sqrt( 66.5 )

t = 8.15 seconds

The time it will take for the rocket to return to ground level will be 2t.

That is, 2 × 8.15 = 16.3 seconds

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3 years ago

A ball rolls horizontally off a table of height 0.6 m with a speed of 9 m/s. How long does it take the ball to reach the ground?

denis23 [38]

Answer: 0.067 s

Explanation:s = Ut + 1/2at^2

0.6 = 9t + 0.5 *10 *t^2

Where a = g =10m/s/s

Solving the quadratic equation

5t^2 + 9t - 0.6=0,

t= 0.067 s and - 1.7 s

Of which 0.067 s is a valid time

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2 years ago

White light is an _____________ mixture of all the colors.<br> a) observable b) unequal c) equal

Musya8 [376]

Answer:

unequal

Explanation:

White light is a combination of all colors in the color spectrum.

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2 years ago

Read 2 more answers

A 65-kg person stands on a scale in a moving elevator while holding a 5.0 kg mass suspended from a massless spring with spring c

disa [49]

Answer:

The question is incomplete. However, I believe, it is asking for the acceleration of the elevator. This is 3.16 m/s².

Explanation:

By Hooke's law, $F = ke$

F is the force on a spring, k is the spring constant and e is the extension or compression.

From the question,

$F = (1.08\text{ kN/m}) \times (6.0 \times 10^{-2}\text{ m}) = 64.8 \text{ N}$

This is the force on the mass suspended on the spring. Its acceleration, a, is given by

$F = ma$

$a = \dfrac{F}{m}$

$a = \dfrac{64.8 \text{ N}}{5\text{ kg}} = 12.96\text{ m/s}^2$

This acceleration is more than the acceleration due to gravity, g = 9.8 m/s². Hence the elevator must be moving up with an acceleration of

12.96 - 9.8 m/s² = 3.16 m/s²

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2 years ago

how to find the change in spring potential energy of the block-spring system from when the block is released to when the block h

Serhud [2]

Answer: Subtract the kinetic energy of the block at x=0.02mx=0.02m from the kinetic energy of the block at x=0.00mx=0.00m.

Explanation:

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2 years ago