Answer:
The answer is the object weighs 5 so 3-5 is 2
Explanation:
I took this test
Answer:
Velocity of a proton,
Explanation:
It is given that,
Potential difference, 
Let v is the velocity of a proton that has been accelerated by a potential difference of 15 kV.
Using the conservation of energy as :

q is the charge of proton
m is the mass of proton




or

So, the velocity of a proton is
. Hence, this is the required solution.
Answer:
GRAVITATIONAL FORCE
Explanation:
We may have noticed that a body thrown upward in air falls back down again after attaining a particular height. The object was able to fall down back due to the effect of gravity acting on it. If there are no force of gravity acting on the body, the body will not fall back but rather disappears into the thin air.
A coin tossed upward in the air which falls back down when released is therefore under the influence of gravity i.e GRAVITATIONAL FORCE while it moves upward after it is released
Answer:
Momentum after collision will be 6000 kgm/sec
Explanation:
We have given mass of the whale = 1000
Initial velocity v = 6 m/sec
It collides with other mass of 200 kg which is at stationary
Initial momentum of the whale = 1000×6 = 6000 kgm/sec
We have to find the momentum after collision
From conservation of momentum
Initial momentum = final momentum
So final momentum = 6000 kgm/sec
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.