B. We can see only one side of the Moon from Earth.
( we only see one side of the moon because the moon rotates around the Earth)
Answer:
a) 3-in. pipe
Explanation:
Given that
Fluid flow is in same amount in the same time it means that volume flow rate is same for the pipes
Volume flow rate
Q = A V
A=Area ,V=Velocity

If diameter d is more then the velocity will be less for same volume flow rate .We also Know that if pressure is more then the velocity will be less.
The second pipe 3 in diameter having more diameter then the velocity will be less but the pressure will be more.
That is why the 3 in diameter is having more pressure than 2 in diameter pipe.
Therefore the answer will be a.
a) 3-in diameter pipe
(a) 1200 rad/s
The angular acceleration of the rotor is given by:

where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for
, we find the final angular speed after 10.0 s:

(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:

If we re-arrange it for t, we get:

where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,

Answer:
a) 3.9 x 10⁻⁵ kg
Explanation:
The amount of mass required to produce the energy can be given by Einstein's formula:

where,
m = mass required = ?
E = Energy produced = 3.5 x 10¹² J
c = speed of light = 3 x 10⁸ m/s
Therefore,

Hence, the correct option is:
<u>a) 3.9 x 10⁻⁵ kg</u>