Answer:
F1 = K Q1 Q2 / R1^2
F2 = K Q1 / 2 * Q2 / (2 R1)^2
F2 / F1 = 1/2 / 4 = 1/8
The new force is 5N (1/2 due to charge and 1/4 due to distance)
Answer:
7.2 V
Explanation:
The three batteries are connected in series to the terminals of the phone: it means that they are connected along the same branch, so the current flowing through them is the same.
This also means that the potential difference across the phone will be equal to the sum of the voltages provided by each battery.
Here, the voltage provided by each battery is
V = 2.4 V
So, the overall voltage will be
V = 2.4 V + 2.4 V + 2.4 V = 7.2 V
Answer:
no
Explanation:
it is faster at the equator
Answer:
(a) 
(b) 
(c) K.E. = 21.168 J
(d) 
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,

- constant downward acceleration,

That a constant upward acceleration of
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,



∴Work by the cord on the block,


We take -ve sign because the direction of force and the displacement are opposite to each other.

(b)
Force on the block due to gravity:

∵the gravity is naturally a constant and we cannot change it


∴Work by the gravity on the block,



(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:


K.E. = 21.168 J
(d)
From the equation of motion:

putting the respective values:

is the speed when the block has fallen 4.2 meters.
Answer:
No. Your friend will not hear the clap when he/she sees it.
Explanation:
It takes time for sound waves to go through a large area. It takes longer if people are in the area rather than it is empty.