The element chlorine has 17 electrons, 17 protons and 18 neutrons....<span> In an atom there is an equal number of electrons and protons. The number of neutrons is found by subtracting the atomic number from the mass number ...
Hope it helps !!!</span>
Answer:
D. The motion cannot be determined without knowing the speeds of the objects before the collision.
Explanation:
This question is tricky! We know the object moving to the left has a greater mass than the one moving to the right. We'd <em>assume</em> they would move to the left because the leftwards object has a greater mass, right?
Not. So. Fast.
We can solve for the objects' final velocity using the formula for momentum, m₁v₁ + m₂v₂ = (m₁ + m₂)v .
Now here's where the trap is sprung: <em>we don't think about the equation</em>. This shows that the final velocity of the objects and the direction depends on both the mass of the objects <em>and</em> their initial velocity.
Basically, what if the 3 kg object is moving at 1 m/s and the 4 kg object is moving at –0.5 m/s? The objects would move to the <em>right</em> after the collision!
Do we know the velocity of these objects? No, right?
That means we <em>can't</em> determine the direction of their motion <u>unless we know their initial, pre-collision velocity</u>. This question is tricky because we look at the 4 kg vs. 3 kg and automatically assume the 4 kg object would dictate the direction of motion. That's not true. It depends on velocity as well.
I hope this helps you! Have a great day!
Answer: B. meteorites, UV rays
The earth's atmosphere plays an important role in shielding the space rocks and meteorites enters inside the earth due to collision with the celestial body. Due to high heat and pressure in the mesospheric layer of the atmosphere these meteorites burned up before reaching the biosphere or hydrosphere system of the earth. The UV rays are protected from entering into the earth atmosphere by the ozone layer present in the stratosphere of the atmosphere. Both meteorites and UV rays can negatively effect the human population. Therefore, the atmosphere is an agent which provides protection against them.
Answer:
Explanation:
This is a problem based on time dilation , a theory given by Albert Einstein .
The formula of time dilation is as follows .
t₁ = 
t is time measured on the earth and t₁ is time measured by man on ship .
A ) Given t = 20 years , t₁ = ? v = .4c
=1.09 x 20
t₁= 21.82 years
B ) Given t = 5 years , t₁ = ? v = .2c
=1.02 x 5
t₁= 5.1 years
C ) Given t = 10 years , t₁ = ? v = .8c
=1.67 x 10
t₁= 16.7 years
D ) Given t = 10 years , t₁ = ? v = .4c
=1.09 x 10
t₁= 10.9 years
E ) Given t = 20 years , t₁ = ? v = .8c
=1.67 x 20
t₁= 33.4 years
