(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:
» An electron is lighter than a proton.
<u>explanation</u><u>:</u>

hence it's mass number is zero

hence it's mass number is 4
<u>Therefore</u><u>,</u><u> </u><u>proton</u><u> </u><u>is</u><u> </u><u>heavier</u><u> </u><u>than</u><u> </u><u>electron</u>
» An electron has a small charge magnitude than a proton.
<u>Explanation</u><u>:</u>
An electron has charge of -1 while proton has charge of +2, therefore electron is less deflected by any energetic fields than a proton
Answer:
Explanation:
1. Impulse, I = F.t
The statement impulse is the product of Force and distance is false.
2. F = m g
Force necessary to lift the object depends on the mass of the object.
statement 2 is false.
3. Joule is equal to Newton times meter.
Statement 3 is false.
4. Work done to lift an object is correct statement.
Statement 4 is true.
5. Kinetic energy of an object is due to motion.
Statement 5 is false.
6. Stopping distance is directly proportional to the square of velocity.
If velocity is doubled, stopping distance is quadrupled.
Statement 6 is false.
When she starts out, he is (40x2.5)= 100 miles ahead of her.
She gains (65-40)= 25 miles on him every hour.
It takes her (100/25)= 4 hours to catch up to him.
I think it's A) Sunspots. I hope this helps:)