Answer:
157.8 J
Explanation:
m = mass of the cylinder = 7 kg
h = height difference in top and bottom of the incline = 2.3 m
g = acceleration due to gravity = 9.8 m/s²
TE = Total Energy at the bottom
PE = Gravitational potential energy at the top
Using conservation of energy
Total Energy at the bottom = Gravitational potential energy at the top
TE = PE
TE = m g h
TE = (7) (9.8) (2.3)
TE = 157.8 J
Answer
Correct answers are 1.an increase or decrease in pressure 2.an increase or decrease in energy
Explanation
All existing matter can undergo phase change it means they may transform from one state to another. phase change of a matter may occur due to change in energy and change in pressures.
for example there is an ice cube which is a solid and if we want to change it phase into liquid water for that purpose we have to supply some energy to ice cube it means we have to give some heat to ice cube. After supplying heat energy to the ice it will turn into water it means there is phase change from solid to liquid due to supplying the heat. Similarly we can change the liquid water into solid ice cube by taking heat energy(reducing temperature) from the liquid water .
In some cases the matter doesn't want to undergo phase transformation. For example, oxygen will solidify at -361.8 degrees Fahrenheit at standard pressure.But , it can change to solid state at warmer temperatures when the pressure is increased.
To solve this problem it is necessary to apply the kinematic equations of motion.
By definition we know that the position of a body is given by
Where
Initial position
Initial velocity
a = Acceleration
t= time
And the velocity can be expressed as,
Where,
For our case we have that there is neither initial position nor initial velocity, then
With our values we have 
, rearranging to find a,
Therefore the final velocity would be
Therefore the final velocity is 81.14m/s
