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4 years ago

How are changes in energy and matter related

Physics

1 answer:

Svetlanka [38]4 years ago

5 0

Answer:

According to Einstein's famous equation, matter can convert into energy (and viceversa) as follows:

$E=mc^2$

where

E is the energy

m is the mass

c is the speed of light ( $3\cdot 10^8 m/s$ )

Given the huge value of $c^2$ , we see that even a tiny amount of matter is able to release a huge amount of energy, when the whole mass is converted into energy. This is precisely what happens in nuclear reactions. For example, in the process of nuclear fusion (that occurs in the core of the stars), two light nuclei fuse together into a heavier nucleus. The mass of the final nucleus is lower than the total mass of the initial nuclei, so part of the mass has been converted into energy according to the equation above: this is why the amount of energy produced by stars is so big.

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Two 65.0 kg ice skaters are standing 2.00 m away from each other in the ice. What is the gravitational attraction between the tw

Paladinen [302]

Answer:

A) 7×10⁻⁸ N

Explanation:

r = Distance between the two skaters = 2 m

m₁ = m₂ = Mass of the two skaters = 65 kg

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

From Newton's Law of Universal gravity

$F=G\frac{m_1m_2}{r^2}\\\Rightarrow F=6.67\times 10^{-11} \frac{65\times 65}{2^2}\\\Rightarrow F=7.045\times 10^{-8}\ N$

∴ Force of gravity between the two skaters is 7×10⁻⁸ N

7 0

4 years ago

A force f is applied horizontally to block A of mass m1 which is in contact with a block B of mass m2. If the surfaces are frict

prohojiy [21]

Answer:

Reaction force = Weight

the force exerted by A on B is equal.

M1a = M2a

Explanation: I think the answer is right if wrong message me.

8 0

2 years ago

Two people are talking at a distance of 3.0 m from where you are and you measure the sound intensity as 1.1 × 10-7 W/m2. Another

Tanya [424]

Answer: $I_2=0.618\times 10^{-7} W/m^2$

Explanation:

Given

Distance between source and receiver $d_1=3 m$

Sound Intensity $I_1=1.1\times 10^{-7} W/m^2$

Distance of of second observer $d_2=4 m$

Intensity varies as

$I\propto \frac{1}{d^2}$

using this

$I=\frac{k}{d^2}$

$\frac{I_1}{I_2}=\frac{d_2^2}{d_1^2}$

$\frac{1.1\times 10^{-7}}{I_2}=\frac{4^2}{3^2}$

$I_2=0.75^2\times 1.1\times 10^{-7}$

$I_2=0.618\times 10^{-7} W/m^2$

6 0

3 years ago

Why does a block of plastic released under water come up to the surface of water.

SCORPION-xisa [38]

A block of plastic released under water will come up to the surface of the water because the density of the plastic is less than the density of water.

<h3>What is density?</h3>

Density is the amount of mass a substance contains per its unit volume. It means the number of particles that can be packed into a unit space of that substance.

<h3>How does density determine whether an object will float or sink?</h3>

When an object is immersed in a liquid, it experiences two forces - gravitational force and an upward buoyant force called upthrust. If the density of the object is more than the density of the liquid, gravitational force will be greater than upthrust and the object will sink, but if the density of the object is less than the density of the liquid, upthrust will be greater than gravitational force and the object will float. That is why a block of plastic will come up to the surface when released under water, because it is less dense than water.

Learn more about density here:

brainly.com/question/6329108

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7 0

2 years ago

What is the force the results from a 3,000kg car accelerating at 20.00 m/s^2?

Phoenix [80]

F = ma = 3000 * 20 = 60 000 N

3 0

4 years ago

Read 2 more answers