This statement is true. Early earth was much cooler than it is today.
This is because the pollution as well as the population number was very small compared to nowadays population and pollution.
The pollution mainly is causing a decay in the ozone layer which protects the earth from uv rays. Thus, more of these rays enter the atmosphere and increase the temperature.
The increase in population along with the decrease in green areas leads to the increase in the percentage of carbon dioxide in the atmosphere, which again leads to an increase in the temperature.
Answer:
Explanation:
Given
mass of box is m
speed of box is v
coefficient of friction 
Box is moving at a constant speed i.e. Net Force on box is zero
i.e. Frictional Force and Force Applied are Equal

The Rate at which power is generated is



Answer:
1. Acceleration
Explanation:
Newtons Second law gives the measure of acceleration
In physics, a force is said to do work<span> if, when acting, there is a displacement of the point of application in the direction of the force. It is expressed as </span><span>Work done = force (N) X distance (m). From the problem statement, the distance traveled is zero. Therefore, the work done is zero as well.</span>