Answer:
Speed of sound inside metal is ≅ 8200 
Explanation:
Given :
Length of metal bar
m
From general velocity equation,

Where
speed of sound in air = 343 
For finding time from above equation,


sec
Since pulses are separated by
sec
So we take time difference,

So speed of sound in metal is,



Answer:
The change in height of the mercury is approximately 2.981 cm
Explanation:
Recall that the formula for thermal expansion in volume is:

from which we solved for the change in volume
due to a given change in temperature 
We can estimate the initial volume of the mercury in the spherical bulb of diameter 0.24 cm ( radius R = 0.12 cm) using the formula for the volume of a sphere:

Therefore, the change in volume with a change in temperature of 36°C becomes:

Now, we can use this difference in volume, to estimate the height of the cylinder of mercury with diameter 0.0045 cm (radius r= 0.00225 cm):

If the force is removed, then there are no other forces acting on the object, the object will continue to move at constant velocity, meaning that it would move in a line tangent to the circular path.
Use direct proportionality: If 1.25 m = 72 N, then 0.55 m = y
0.55 m × 72 = 39.6.
39.6÷1,25 gives you your answer which is 31.68 N.
Physics can be used in a variety of ways, a specific example would be rollercoaster. Physics can be used to determine the speed at which a rollercoaster can travel without going off the rails or when it needs to begin to slow down to make a sharp turn.