Answer:
option (D)
Explanation:
Here initial rotation speed is given, final rotation speed is given and asking for time.
If we use
A) θ=θ0+ω0t+(1/2)αt2
For this equation, we don't have any information about the value of angular displacement and angular acceleration, so it is not useful.
B) ω=ω0+αt
For this equation, we don't have any information about angular acceleration, so it is not useful.
C) ω2=ω02+2α(θ−θ0)
In this equation, time is not included, so it is not useful.
D) So, more information is needed.
Thus, option (D) is true.
Answer:
Explanation:
When the two dissimilar bodies rubbed together, they the both of the bodies becomes charged. One of the body gets positive charge and the other body gets negative charge.
the positively charged body loses some electrons and the negatively charged body gains some electrons.
According to the properties of charge when the plastic rod is rubbed with the fur, the plastic rod has a tendency to get the negative charge and the fur has a tendency to get positive charge.
So,
When we rub a plastic rod with a piece of fur, electrons--------------transfer from fur----------------to the -------plastic-----. In the result charging fur with -positive-----------charge and plastic rod with-----negative--------charge.
Answer:
a. 
b. 
Explanation:
Using the triangle theorem both triangle the woman makes between the light so the rate of change of length can use geometry first

Solve to find the rate relation


Now the rate of the change rate


Finally the rate of her shadow moving



According to above question ~
Let's find the charge (q) by using formula ~
Hence, 12 coulombs of charge flow past any point in the wire in 3 seconds