We have the equation of motion
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here s = 300 m, u = 0 m/s, a = 9.81
Substituting

Now we have v = u+at, where v is the final velocity
Here u = 0 m/s, a= 9.81
and t = 7.82 seconds
Substituting
v = 0+9.8*7.82 = 76.68 m/s
The speed with which the penny strikes the ground = 76.68 m/s.
No the substance will remain the same substance as before.
Answer:
Capacitance of the second capacitor = 2C
Explanation:

Where A is the area, d is the gap between plates and ε₀ is the dielectric constant.
Let C₁ be the capacitance of first capacitor with area A₁ and gap between plates d₁.
We have

Similarly for capacitor 2

Capacitance of the second capacitor = 2C
Answer:
123 J transfer into the gas
Explanation:
Here we know that 123 J work is done by the gas on its surrounding
So here gas is doing work against external forces
Now for cyclic process we know that

so from 1st law of thermodynamics we have


so work done is same as the heat supplied to the system
So correct answer is
123 J transfer into the gas
Explanation:
To find the answer use the equation speed of light=wavelength multiplied by frequency (c=lambda*f) by substituting the value for the frequency the the speed of light