Answer:
13.7%
Explanation:
Given that,
Heat absorbed by the engine = 97.2 kJ
Heat exhausted by the engine in each cycle = 83.8 kJ
We need to find the efficiency of the engine. It is calculated by the formula.

so, the efficiency of heat engine is 13.7%.
Explanation:
It is given that,
Total weight of the piston, W = F = 70 N
Area of the piston, 
Let P is the pressure exerted on the piston by the gas. The force per unit area is called the pressure exerted pressure of the gas. Mathematically, it is given by :



We know that the atmospheric pressure is given by :

So, the pressure is given by :



Hence, this is the required solution.
Answer:
Explanation:
According to Newton's third law, every action has an equal and opposite reaction
so it tells us that the force exerted by the earth on the spacecraft is equal to the force exerted by the spacecraft on the earth. But we do not see the earth moving towards the spacecraft because the inertia of the spacecraft is very less than the inertia of the earth.
The sun is bigger than the earth, therefore it has more gravitational force than the earth.
A volt-ampere is the product of the voltage and the current (measured in amperes) of the electricity on a line. Voltage is electric potential difference in charge between two points in an electrical field. it is measured in volts. while the Current is the flow of electrical charge which is often carried by moving electrons in a wire or a conductor. Current is measured in Amperes.