Choices 'C' and 'D' are both correct.
(Except in 'C', changing the temperature from 1°C to 3°C is not usually
described as 'cooling', and it's not the water's 'mass' that changes. But
water does contract in volume during that change.)
Answer:
See the explanation below.
Explanation:
A lever is a simple machine that changes the magnitude and direction of the force applied to move an object. Minimizes the force needed to lift the object.
By means of the following image, we can see the principle of operation of a lever.
The load can be moved thanks to the force multiplied by the distance to the fulcrum.
Distance , d = a+b

The unit of d is in meter and t is in seconds.
So the unit of a a must be meter.
Now we have unit of b

is meter.
So unit of b*

= meter
Unit of b = meter/

So unit of a = m and unit of b = m/

.
The cause of attraction and movement in terms of repulsion and attraction is caused electromagnetic properties of the particles. The basic rule of magnetism is like attracts unlike while like repels like. This rule is useful in the application of electricity
You’re correct, it’s gravity