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2 years ago

What was the vertical component of her acceleration during push-off? the positive direction is upward?

1 answer:

5 0

<span>The answer of these two problems are : A) a = (F-W)/m = (100-500)/500/g = 9.8*500/500 = +9.8 m/sec^2 B) a1 = +9.8-g = 0</span>

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How much force is required to accelerate a 2kg mass at 3 m/s2? answer key?

mr Goodwill [35]

F = ma so u can plug in the given numbers and solve:

F = (2)(3)

4 0

3 years ago

A person pulls a bucket of water up from a well with a rope. Assume the initial and final speeds of the bucket are zero (Vi-Vf-0

n200080 [17]

Answer:

This a closed system because the mass of the system is conserved

The energy system that undergoes change is the Potential energy system

The energy system diagram is shown on the first uploaded image

Work done = Change in gravitational potential energy

So solving algebraically for work done would be

Work done = $m*g*h$

where m is mass

g is acceleration due to gravity

and h is the height

Work done in terms of force and distance is = mg

where m is mass of bucket and

g is acceleration due to gravity

Explanation:

a) At the start, potential and kinetic energy were zero. so, energy is zero.

As the person pulls the bucket up, the potential energy becomes mgh.

so,final energy will be consisting of only potential energy.

B) Here work done is equal to change in gravitational potential energy.

W = $\Delta P.E$

W = m*g*h

where g = 9.9 m/ $s^2$

C) Work = force * distance

mgh = force * h

force = mg

force = weight of bucket

6 0

2 years ago

If the accuracy in measuring the position of a particle increases, the accuracy in measuring its velocity will Group of answer c

Sindrei [870]

Answer:

The correct answer is Option A (decrease).

Explanation:

According to Heisenberg's presumption of unpredictability, it's impossible to ascertain a quantum state viewpoint as well as momentum throughout tandem.
Also, unless we have accurate estimations throughout the situation, we will have a decreased consistency throughout the velocity as well as vice versa though too.

Other given choices are not connected to the given query. Thus the above is the right answer.

5 0

2 years ago

In which case would electrical potential energy be built up and stored in the electric field? a) A positive charge is moved towa

mr_godi [17]

Answer:

The correct option is B

Explanation:

Although, it is common knowledge that in an electric field, unlike charges attract and like charges repel. However, to build up an electric potential, a positive charge is brought close to another positive charge - this causes work done to be changed to electric potential energy and stored in the electric field.

It should however be noted that when a negative charge is moved away from a positive charge, the negative charge gains electric potential energy.

5 0

2 years ago

Any help is appreciated please

stiv31 [10]

Answer:

C. It speeds up, and the angle increases

Explanation:

We can answer by using the Snell's law:

$n_i sin \theta_i = n_r sin \theta_r$

where

$n_i, n_r$ are the refractive index of the first and second medium

$\theta_i$ is the angle of incidence (measured between the incident ray and the normal to the surface)

$\theta_r$ is the angle of refraction (measured between the refracted ray and the normal to the surface)

In this problem, light moves into a medium that has lower index of refraction, so

$n_r < n_i$

We can rewrite Snell's law as

$sin \theta_r =\frac{n_i}{n_r}sin \theta_i$

and since

$\frac{n_i}{n_r}>1$

this means that

$sin \theta_r > sin \theta_i$

which implies

$\theta_r > \theta_i$

so, the angle increases.

Also, the speed of light in a medium is given by

$v=\frac{c}{n}$

where c is the speed of light and v the refractive index: we see that the speed is inversely proportional to n, therefore the lower the index of refraction, the higher the speed. So, in this problem, the light will speed up, since it moves into a medium with lower index of refraction.

4 0

3 years ago