What is Newton's first law

Rearrange the equation = KE -1 2 - my? to solve for v. Show your work.

vesna_86 [32]

Answer:

See below

Explanation:

KE = 1/2 m v^2 multiply both sides by 2

2 (KE) = mv^2 divide both sides by m

2(KE) / m = v^2 sqrt both sides

√ [(2KE)/m ] = v

3 0

2 years ago

PLEASE HELP! 3 Questions, 10 points a question, will give brainliest.

Basile [38]

1) Mechanical energy is conserved in all the 4 situations

2) True

3) The potential energy of the block is 490 J

Explanation:

1)

Mechanical energy is the sum of potential energy (PE) and kinetic energy (KE) of a body:

$E=PE+KE$

According to the law of conservation of energy, in absence of non-conservative forces (such as air resistance, friction...), the mechanical energy of a body is always conserved.

This means that the mechanical energy is conserved in all the situations described. More specifically:

- Child on a swing : there is a continuous conversion between kinetic energy and gravitational potential energy

- Pendulum : there is a continuous conversion between kinetic energy and gravitational potential energy

Bow and Arrow : there is a conversion of energy from elastic potential (when the bow is stretched) to kinetic energy (when the arrow is shot)

Roller Coaster: there is a continuous conversion between kinetic energy and gravitational potential energy

2)

As we said, the mechanical energy of the object falling down at any point of the fall is

$E=KE+PE$

where KE is the kinetic energy and PE is the potential energy. The value of E is constant, since the mechanical energy is conserved.

The potential energy is given by

$PE=mgh$

where m is the mass of the object, g is the acceleration of gravity, h is the height of the object above the ground.

As the object falls, its height $h$ decreases, and therefore, the potential energy PE also decreases. But we said that E must remain constant: therefore, if PE decreases, this means that KE increases, therefore as the object falls, the potential energy is converted into kinetic energy (in fact, the speed of the object increases). So the statement is true.

3)

The potential energy of an object is given by the equation

$PE=mgh$

where

m is the mass of the object

$g=9.8 m/s^2$ is the acceleration of gravity

h is the height of the object relative to the ground

For the block in this problem, we have:

m = 10 kg

h = 5 m

Substituting, we find its potential energy:

$PE=(10)(9.8)(5)=490 J$

Learn more about potential energy and kinetic energy:

brainly.com/question/6536722

brainly.com/question/1198647

brainly.com/question/10770261

#LearnwithBrainly

8 0

3 years ago

Shah did not trust the results of an experiment that she had read about, so she is conducting the experiment herself. She goes t

Hitman42 [59]

The question is incomplete, the complete question is;

Shah did not trust the results of an experiment that she had read about, so she is conducting the experiment herself. She goes through the same set of steps and measures the effect of the amount of sugar on a single organism.

Which best describes what Shah is doing?

replication

repetition

both repetition and replication

neither repetition nor replication

Answer:

replication

Explanation:

Replication in scientific experiments refer to the process of going through all the steps in an experiment in order to obtain the same set of results initially obtained.

All scientific experiments is expected to be replicated under identical experimental conditions. If the results obtained by a scientific investigation cannot be replicated under identical circumstances by other scientists, then the scientific data must be taken with a pinch of salt.

Shah is expected to obtain almost exactly the same data as the original researchers who first published the data.

5 0

2 years ago

Read 2 more answers

The eyes of many older people have lost the ability to accommodate, and so an older person’s near point may be more than 25 cm f

tensa zangetsu [6.8K]

Answer:

Smaller refractive power

Explanation:

The refractive power of an eye is the extent to which it can converge or diverge the light rays.

Near point is the the closest point for an eye such that when an object is placed at that point the image it forms is sharp and clearly visible to the eye.

A the person ages, the ciliary muscles of the eyes weakens and as a result the lens contracts and the formation of the image takes place behind the retina instead of forming at the retina.

Thus the near point also increases and the refractive power becomes smaller.

4 0

3 years ago

a sprinter with a mass of 80kg accelerates uniformly from 0 m/s to 9 m/s in 3 s. a.)what is the runners acceleration? b.) what i

Katyanochek1 [597]

Part A:
Acceleration can be calculated by dividing the difference of the initial and final velocities by the given time. That is,
a = (Vf - Vi) / t
where a is acceleration,
Vf is final velocity,
Vi is initial velocity, and
t is time

Substituting,
a = (9 m/s - 0 m/s) / 3 s = 3 m/s²
ANSWER: 3 m/s²

Part B:
From Newton's second law of motion, the net force is equal to the product of the mass and acceleration,
F = m x a
where F is force,
m is mass, and
a is acceleration

Substituting,
F = (80 kg) x (3 m/s²) = 240 kg m/s² = 240 N

ANSWER: 240 N 

Part C:
The distance that the sprinter travel is calculated through the equation,
d = V₀t + 0.5at²

Substituting,
d = (0 m/s)(3 s) + 0.5(3 m/s²)(3 s)²
d = 13.5 m

ANSWER: d = 13.5 m

3 0

3 years ago

What is Newton's first law​

What is Newton's first law