Answer:
V=Bh
Explanation:
B h is used for rectangular solids and cylinders
Average speed is the ratio of total distance moved by Chi in total time interval
So here we will have
Total distance = 100 m + 400 m

Total time taken = 5 min + 15 min = 20 min

now by the formula of average speed we know that



so average speed will be 1.5 km/h
Answer:
This is due to a relative decrease in atmospheric pressure in high places.
Explanation:
Given that atmospheric pressure decreases at the higher point or ground, this reduced atmospheric pressure, however, will be unable to contain the Mercury in the barometer tube.
Therefore, at the top of the mountain where the air pressure is low, the barometer reading ultimately goes down.
Hence, the level of mercury falls in a barometer while taking it to a mountain "due to a relative decrease in atmospheric pressure in high places."
Answer:
The change in potential energy is 
Explanation:
From the question we are told that
The magnitude of the uniform electric field is 
The distance traveled by the electron is 
Generally the force on this electron is mathematically represented as
Where F is the force and q is the charge on the electron which is a constant value of 
Thus


Generally the work energy theorem can be mathematically represented as

Where W is the workdone on the electron by the Electric field and
is the change in kinetic energy
Also workdone on the electron can also be represented as
Where
considering that the movement of the electron is along the x-axis
So

substituting values


Now From the law of energy conservation
Where
is the change in potential energy
Thus
