formula for gravitational P.E =mgh
Solution:-mass=3kg height=5metre and gravity=9.8 or 10m/sec² so P.E=mgh , 3×9.8×5=147kgm²/sec²
<span>Velocities are vectors so we can add them!
Let's let +x be East and -x be West.
-0.9 + 2.7 = 1.8
Since our answer is positive that means East so the answer is C.</span>
Answer:
Water gains energy during evaporation and releases it during condensation in the atmosphere
Explanation:
In the water cycle, heat energy is gained or lost by water as it undergoes various processes in the cycle.
In evaporation, water molecules gains energy because the molecules of water vibrate faster and become more energetic. Hence they are able to escape into the atmosphere from the surface of the liquid.
In condensation, the molecules of gaseous water looses energy and becomes liquid.
Hence, water gains energy during evaporation and releases it during condensation in the atmosphere.
Answer:
(a) 
(b) 
(c) 
Explanation:
(a) According to Newton's second law, the acceleration of a body is directly proportional to the force exerted on it and inversely proportional to it's mass.

(b) According to Newton's third law, the force that the sled exerts on the girl is equal in magnitude but opposite in the direction of the force that the girl exerts on the sled:

(c) Using the kinematics equation:

For the girl, we have
and
. So:

For the sled, we have
. So:

When they meet, the final positions are the same. So, equaling (1) and (2) and solving for t:

Now, we solve (1) for 

Answer:

Explanation:
<u>Elementary charge</u>
The elementary charge, denoted by the symbol e is the electric charge carried by a proton or, equivalently, the magnitude of a negative electric charge carried by an electron, which has charge −e.
The value of the elementary charge is a fundamental constant in physics:

If a metal sphere has an excess of +5 elementary charge, then it has a net charge of:

