Answer:
Explanation:
The area of a circle is given b
A=πr²
Then,
dA/dr= 2πr
Also give that,
dr/dt=30m/hr, r=100m
We want to find dA/dt
dA/dt=dA/dr×dr/dt
dA/dt= 2πr × 30
dA/dt= 2 ×π ×100×30
dA/dt=18849.56m²/s.
The rate of the area is 18849.56m²/s
1 ampere is 1 coulomb of charge moving through a cross section in one second.
Answer:
a) 2seconds.
Explanation:
The period of oscillation will not change . It will still be 2seconds although the length was doubled to 8cm.
This is because the amplitude does not change oscillation time.
Explanation:
Given that,
Charge 1, 
Charge 2, 
The distance between charges, r = 1.99 m
To find,
The electrostatic force and its nature
Solution,
(a) The electric force between two charges is given by :



(b) As the magnitude of both charges is positive, then the force between charges will be repulsive.
Therefore, this is the required solution.
Answer:
Part a)

Part b)

Explanation:
As we know that initial speed of the car is



now we have



Part a)
As we know that acceleration is constant here
so we have


Part b)
distance moved by the car is given as

now we have

