Answer:
a) t=10.2s
b) The 2g-cube moves first
Explanation:
Since the electric force is the same on both cubes and so is the coefficient of static friction, the first one to move will be the one with less mass.
So, on the 2g-cube the sum of forces are:

Replacing the friction on the first equation:
Thus 
The electric force is:
Solving for q:
q=71.44nC
This amount divided by the rate at which they are being charged:
t = 71.44nC / 7nC/s = 10.2s
Answer: 2R
Explanation:
Here the person travels пR distance. We know that the circumference of a circle is 2πR. So your imaginated person has traveled the distance which is half of the circumference of the circle. And this distance is equal to its diameter. We know that diameter of a circle is two times larger than the radius. So the person's displacement is two times of the radius, means 2R. [Here 'R' means the radius of the circle]
Which amplitude of the following longitudinal waves has the greatest energy?
amplitude = 10 cm; wavelength = 6 cm; period = 4 seconds
Answer:
ΔLa/ΔLb = 1
Explanation:
The change in length of a solid is given by the following formula:
ΔL = α L ΔT
where,
ΔL = Change in length
α = coefficient of linear expansion
L = Original Length
ΔT = Change in Temperature
Since, the length and change in temperature for both rods are same. Also, the material of each rod is same, which implies that coefficient of linear expansion for both rods is same. Hence, the ratio of change in length of both rods will be:
<u>ΔLa/ΔLb = 1</u>
Answer:
a) 600nm
b) 300nm
Explanation:
the path difference = 2t
t = thickness of the film
L' = wavelength of light in film = L/n
L = wavength of light in air
n = refractive index of glass
(a)
for destructive interference 2t = L'/2 = L/2n
L = 4*t*n
= 4*120*10^-9*1.25
L = 600 nm
(b)
for constructive interference 2t = L' = L/1.25
L = 2tn
= 2 × 1.25 × 120nm
= 300 nm