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.
<h2>Answer: decreasing</h2>
An RC circuit is an electrical circuit composed of resistors and capacitors, where the charging time
of the circuit is proportional to the magnitude of the electrical resistance
and the capacity
of the capacitor.
As shown below:
In this context, the electrical resistance is the opposition to the flow of electrons when moving through a conductor.
Therefore:
<h2>When a capacitor is being charged in an RC circuit, the current flowing through a resistor <u>decreases</u>.</h2>
And the correct option is b.
It’s c because it’s not Control so that means that it would be broken and non fix able
Answer:
B) Power is the rate at which work is done