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3 years ago

The weigth of a body decrease in a coal mine why?

Physics

2 answers:

pychu [463]3 years ago

5 0

Answer

Gravitational force is between two object caused by energy in mass. Here when you are in a mine the radius of the earth in case of calculating gravity is reduced to the length between you and the center.

This means the mass of earth is decreasing even though the distance is decreasing. Relative to the decrease in distance squared the decrease in the mass of the second object(earth) is more. As a result your weight decreases.

posledela3 years ago

5 0

Answer:

Explanation: that means as you descend into the earth, all of the mass in all the shells above you gets canceled. If the centre of the earth were not molten iron, but instead hollowed out, you would be weightless inside.

The physics problem is actually a little more general. It applies to inverse square force laws such as the electrical force. So if you put an electron inside a positively or negatively charged sphere, it will also have a net force on it of zero.

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If a child starts from rest at point A and lands in the water at point B, a horizontal distance L = 2.52 m from the base of the

tamaranim1 [39]

Answer:

The height of the water slide is 0.878 m

Explanation:

Given that,

Distance = 2.52 m

Suppose Children slide down a friction less water slide that ends at a height of 1.80 m above the pool.

We need to calculate the time

Using equation of motion

$s=ut+\dfrac{1}{2}gt^2$

Put the value in the equation

$1.80=0+\dfrac{1}{2}\times9.8\times t^2$

$t^2=\dfrac{1.80\times2}{9.8}$

$t=\sqrt{\dfrac{1.80\times2}{9.8}}$

$t=0.606\ sec$

We need to calculate the velocity

Using formula of velocity

$v = \dfrac{d}{t}$

Put the value into the formula

$v=\dfrac{2.52}{0.606}$

$v=4.15\ m/s$

We need to calculate height

Using conservation of energy

$\dfrac{1}{2}mv^2=mgh$

$h=\dfrac{v^2}{2g}$

Put the value into the formula

$h=\dfrac{4.15^2}{2\times9.8}$

$h=0.878\ m$

Hence, The height of the water slide is 0.878 m.

4 0

3 years ago

A ferry approaches shore, moving north with a speed of 6.2 m/s relative to the dock. A person on the ferry walks from one side o

jasenka [17]

Speed of Ferry is towards North with magnitude 6.2 m/s

Here if we assume that North direction is along Y axis and East is along X axis then we can say

$\vec v_f = 6.2 \hat j$

Now a person walk on ferry with speed 1.5 m/s towards east with respect to Ferry

so it is given as

$\vec v_{pf} = 1.5 \hat i$

also by the concept of relative motion we know that

$\vec v_{pf} = \vec v_p - \vec v_f$

now plug in all values in it

$1.5 \hat i = \vec v_p - 6.2 \hat j$

$\vec v_p = 1.5 \hat i + 6.2 \hat j$

now if we need to find the speed of the person then we need to find its magnitude

so it is given as

$v = \sqrt{1.5^2 + 6.2^2}$

$v = 6.37 m/s$

7 0

3 years ago

Do you think it is possible to control the magnetic properties of a magnet? Can a magnet be turned on and off?

Sunny_sXe [5.5K]

Answer:

Yes it is possible to control to some extent.

Explanation:

In general there are two types of magnets : permanent and temporary (electromagnets).

Electromagnets can be controlled since it basically depends on electricity. By switching on and off the electric supply the magnets also can be switched on and off respectively. We can also control the intensity of magnetic power.

On the other hand permanent magnet cannot be switched on and off but the magnetic properties can be altered event to an extent when it loses all its magnetic properties. It can be caused by high temperature, physical impact and also exposure to other magnetic fields. For every element there is a point of temperature called curie temperature above which the permanent magnet loses its magnetic properties. This can be brought back again by induced magnetism. The only issue is that induced magnetism work in most cases but not in all.

6 0

3 years ago

4.) An apartment building is on fire and a guy is trapped on the fire escape ladder. There is a

Tems11 [23]

Answer:

5.3 m/s

Explanation:

First, find the time it takes for him to fall 7m.

y = y₀ + v₀ t + ½ at²

0 = 7 + (0) t + ½ (-9.8) t²

0 = 7 − 4.9 t²

t ≈ 1.20 s

Now find the velocity he needs to travel 6.3m in that time.

x = x₀ + v₀ t + ½ at²

6.3 = 0 + v₀ (1.20) + ½ (0) (1.20)²

v₀ ≈ 5.27 m/s

Rounded to two significant figures, the man must run with a speed of 5.3 m/s.

3 0

3 years ago

Where should a force be applied on a lever arm to produce the most torque

nignag [31]

The answer is,

<u>Farthest from the axis of rotation</u>

Please rate <u>Brainliest</u> (:

3 0

3 years ago

The weigth of a body decrease in a coal mine why?​

The weigth of a body decrease in a coal mine why?