All categories

2 years ago

According to the law of conservation of energy, mechanical energy can be changed to heat energy.

Physics

1 answer:

Leno4ka [110]2 years ago

8 0

Answer:

The answer to this question is given below in this explanation section.

Explanation:

" law of conservation of energy"

The law of conservation of energy states that energy can neither be created nor destroyed only converted from one form of energy into another.This mean that a system always has a same account of a energy,unless it is added from the outside.This is particularly confusing in the case of non conversation forces,where energy is converted from ,mechanical energy into thermal energy.but the overall energy does remain the same.The only way to use energy is to transform energy from one form to another.

The amount of energy in any system than it is determined by the following equation.

Ut=Ui +W+Q

Ut is the total internal energy of a system.
Ui is the initial internal energy of a system.
W is the work done by or on the system.
Q is the heat added to or removed by the system.

It is also possible to determined the change in internal energy of the system using the equation.

ΔU=W+Q

The mechanical energy of a system increases provided their is no loss of energy due to friction.The energy would transform to kinetic energy when the speed is increasing.Te mechanical energy of a system remain constant provided their is no loss of energy due to friction.

The law of conversation of energy which say that in a closed system total energy is conserved that is it constant.

KE1 + PE1=KE2+PE2

You might be interested in

In my trigonometry class, we were assigned a problem on Angular and Linear Velocity.

Rzqust [24]

1) 0.0011 rad/s

2) 7667 m/s

Explanation:

The angular velocity of an object in circular motion is equal to the rate of change of its angular position. Mathematically:

$\omega=\frac{\theta}{t}$

where

$\theta$ is the angular displacement of the object

t is the time elapsed

$\omega$ is the angular velocity

In this problem, the Hubble telescope completes an entire orbit in 95 minutes. The angle covered in one entire orbit is

$\theta=2\pi$ rad

And the time taken is

$t=95 min \cdot 60 =5700 s$

Therefore, the angular velocity of the telescope is

$\omega=\frac{2\pi}{5700}=0.0011 rad/s$

For an object in circular motion, the relationship between angular velocity and linear velocity is given by the equation

$v=\omega r$

where

v is the linear velocity

$\omega$ is the angular velocity

r is the radius of the circular orbit

In this problem:

$\omega=0.0011 rad/s$ is the angular velocity of the Hubble telescope

The telescope is at an altitude of

h = 600 km

over the Earth's surface, which has a radius of

R = 6370 km

So the actual radius of the Hubble's orbit is

$r=R+h=6370+600=6970 km = 6.97\cdot 10^6 m$

Therefore, the linear velocity of the telescope is:

$v=\omega r=(0.0011)(6.97\cdot 10^6)=7667 m/s$

4 0

3 years ago

From the gravitational law calculate the weight W (gravitational force with respect to the earth) of a 89-kg man in a spacecraft

zhannawk [14.2K]

Answer:

$W=\frac{773}{4.45}=173.76 l b f$

Explanation:

$W=\frac{G \cdot m_{e} \cdot m}{(R+h)^{2}}$

The law of gravitation

$G=6.673\left(10^{-11}\right) m^{3} /\left(k g \cdot s^{2}\right)$

Universal gravitational constant [S.I. units]

$m_{e}=5.976\left(10^{24}\right) k g$

Mass of Earth [S.I. units]

$m=89 kg$

Mass of a man in a spacecraft [S.I. units]

$R=6371 \mathrm{~km}$

Earth radius [km]

Distance between man and the earth's surface

$h=261 \mathrm{~km} \quad[\mathrm{~km}]$

ESULT $W=\frac{6.673\left(10^{-11}\right) \cdot 5.976\left(10^{24}\right) \cdot 89}{\left(6371 \cdot 10^{3}+261 \cdot 10^{3}\right)^{2}}=773.22 \mathrm{~N}$

$W=\frac{773}{4.45}=173.76 l b f$

4 0

2 years ago

9. When making a circuit, why is gold wiring not used?

daser333 [38]

Answer:

Gold is not used for making electric wires because it is too rare, and too costlier than Copper. Silver and copper are used for making wires. Copper is almost used in electric lines

4 0

3 years ago

Which of the 3 states of matter is easier to increase the temperature by one degree; in a liquid, in a solid, or in a gas?

Mashcka [7]

Answer:

gas

Explanation:

this is bcz they have higher kinetic energy compared to liquids and gases

4 0

3 years ago

The half-life of Co-55 is 175 hours. How much of a 4000 g of Cobalt-55 sample would be left after 525 hours?

Harrizon [31]

We know that whatever amount we start with, half of it decays and forms atoms of other elements in 175 hours. So in order to figure out how much is left after 525 hours, we'll need to know how many half-lifes pass in that amount of time.

Well, (525 divided by 175) is exactly 3 half-lifes. So this will be easy.

-- After 1 half-life . . .

. . . . . 50% decays, 50% is still there.

-- After the 2nd half-life . . .

. . . . . (half of the leftover 50%) = another 25% decays, 25% is left.

-- After the 3rd half-life . . .

. . . . . (half of the leftover 25%) = another 12.5% decays, 12.5% is left.

12.5% of 4,000g = (0.125 x 4,000g) = 500 g .

============================================

Another way:

After 1 half-life, 1/2 is left.

After 2 half-lifes, 1/4 is left.

After 3 half-lifes, 1/8 is left.

1/8 of 4,000g = (4,000g/8) = 500 g .

5 0

3 years ago