Answer:
1. Elastic collision
2. Inelastic collision
Explanation:
Elastic collision: collision is said to be elastic if total kinetic energy is not conserved and if there is a rebound after collision
the collision is described by the equation bellow

Inelastic collision: this type of collision occurs when the total kinetic energy of a body is conserved or when the bodies sticks together and move with a common velocity
the collision is described by the equation bellow

It be desirable to use an energy resource that does not produce greenhouse gases because it contribute to climate change
.
Option C
<u>Explanation:</u>
Greenhouse gases are the toxic gases that contribute to the "greenhouse effect". Greenhouse gases have the ability to absorb and emit some of the outgoing energy that is radiated by the Earth's surface, eventually causing the heat to get accumulated in the "lower atmosphere". It is always beneficial to use Renewable Energy sources such as Wind, solar and water which gives no harm to the environment and climate with no greenhouse gas emissions.
<u>For example:</u> If we have to generate electricity, there will be no greenhouse gas production at the beginning and a very less amount of production at the entire life cycle.
If the mass of both of the objects is doubled, then the force of gravity between them is quadrupled; and so on. Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces
C.There is an invisible magnetic field around the magnet where it exerts magnetic force
Answer:
(a) 5142.86 m
(b) 317.5 m/s
(c) 49.3 degree C
Explanation:
m = 100 kg, Q = 1200 kcal = 1200 x 1000 x 4.2 = 504 x 10^4 J
(a) Let the altitude be h
Q = m x g x h
504 x 10^4 = 100 x 9.8 x h
h = 5142.86 m
(b) Let v be the speed
Q = 1/2 m v^2
504 x 10^4 = 1/2 x 100 x v^2
v = 317.5 m/s
(c) The temperature of normal human body, T1 = 37 degree C
Let the final temperature is T2.
Q = m x c x (T2 - T1)
504 x 10^4 = 100 x 4.1 x 1000 x (T2 - 37)
T2 = 49.3 degree C