There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:
- radius of the hill:
Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car
(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,
, so we can write:
(1)
By rearranging the equation and substituting the numbers, we find N:
(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:
(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:
from which we find
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.
The first law of thermodynamics states that energy cannot be created nor destroyed. It can be transformed from one form of energy to another, but the energy in an isolated system remains constant.
The answer then would be letter B. False.
Answer:
11212121221212121212121212121212121212121212121221212
Explanation:
12121212 i am jj and i am 8