Answer:
The lose of thermal energy is, Q = 22500 J
Explanation:
Given data,
The mass of aluminium block, m = 1.0 kg
The initial temperature of block, T = 50° C
The final temperature of the block, T' = 25° C
The change in temperature, ΔT = 50° C - 25° C
= 25° C
The specific heat capacity of aluminium, c = 900 J/kg°C
The formula for thermal energy,
<em>Q = mcΔT</em>
= 1.0 x 900 x 25
= 22500 J
Hence, the lose of thermal energy is, Q = 22500 J
Explanation:
In local galactic group the force of expansion of universe is overcome by the force of attraction due to gravity. Best example is our own galaxy milky way and another giant galaxy in our local group Andromeda. Andromeda having enormous gravity is pulling milky way towards itself, overcoming the force of expansion.
So, there are possibilities of collision despite the expansion of universe at a rapid pace. It is estimated that the milky way and Andromeda will collide each other after about 50 billion years from now.
Out of the given options, ‘it is described as a fundamental force and therefore does not depend on other forces’ is the true statement about gravity.
Answer: Option B
<u>Explanation:
</u>
As we all know that there are four fundamental forces existing in the universe- Electromagnetic force, strong forces, weak forces and the gravitational force.
These are the forces that don’t depend on any other physical force to draw a considerable impact on the physical objects. The gravitational force can be defined as,

Where,
G = Gravitational Constant
= Masses of two substances under consideration
R = distance between the two substances.
Looking upon the formula of gravitational force we can easily estimate that the gravitational force relies on the mass of substances and the relative distance between them. There is no factor than the air friction that hinders the gravitational force and that too in a negligible amount.