Matter either loses or absorbs energy when it changes from one state to another. For example, when matter changes from a liquid to a solid, it loses energy. The opposite happens when matter changes from a solid to a liquid. For a solid to change to a liquid, matter must absorb energy from its surroundings.
Answer:
2nd one if you ask me
almost every baby stats to talk after their a year old
RADIATION BELTS....... I think but it should be radiation belt
Answer:
(a) -472.305 J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305 J=-472.305 J
(b)
From fundamental kinematic equation

Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
but a=\mu g hence

Answer:
option A
Explanation:
given,
Kinetic energy of the car = 2000 J
speed of the car is doubled
we know,

........(1)
now, speed of the car is doubled
v' = 2 v


from equation (1)



Hence, the Kinetic energy would be equal to 8000 J.
The correct answer is option A.