<span>1.
</span><span>Efficiency is the
measure of how efficient a process is. It is used to assess the ability of a
process in avoiding waste energy, materials, money and time in doing a
desirable output. It is calculated as;
Efficiency = useful energy ouput / total energy input</span>
<span>.40 = useful work / 200</span>
<span>useful work = 80 joules</span>
<span> The statement that best accounts for these different opinions is: scientists propose contradictory ideas to include all possibilities. This statement refers to the scientific method, that is a set of different techniques for investigating phenomena and gaining new knowledge that can improve or correct the previous one. As a result, analysis based on contradicting opinions leads to the progress in scientific sphere.</span>
Answer:0.27
Explanation:
Given
One worker Pushes with force 
other Pulls it with a rope of rope 
mass of crate 
both forces are horizontal and crate slides with a constant speed
Both forces are in the same direction so Friction will oppose the forces and will be equal in magnitude of sum of two forces because crate is moving with constant speed i.e. net force is zero on it

where
is the friction force



where
is the coefficient of static friction



Answer:
Isaac Newton
Explanation:
Newton's laws of motion, three statements describing the relations between the forces acting on a body and the motion of the body.