Answer:
0.237 (23.7 %)
Explanation:
The thermal efficiency of an engine is given by:
where
W is the useful work output of the engine
is the heat in input
Here we have:
and the work done is the total heat in input minus the heat exhausted:
So, the efficiency is
(23.7 %)
The reason an astronaut in an earth satellite feels weightless is that the astronaut is falling.
Option a
<u>Explanation: </u>
The other options except Option is not applicable since the gravitational force is a long range force, in which the satellite revolves very close to the surface of the Earth where the gravity is felt.The zero weight experienced by the astronaut in a satellite is due to the earth pulling along with satellite. Due to gravitational force of the Earth,the astronaut falls freely .
But why not the satellite comes down due to gravity when its launched in space. The fact is that the satellite is launched with velocity of tangent direction and it is very high. The centripetal force balances the gravity.
Answer:
maximum force (in N) can you exert horizontally on the crate without moving it = 564.075 N
Explanation:
Given data:
mass m= 115 kg
coefficient of friction μ =0.5
according to newton law of motion the net force acted on body is given by
here the body is in rest ,
N= it is the normal reaction force
N= mg = 115×9.81
therefore,
1. The chemical reaction produced by Carlo's fire is exergonic because energy is "going out". As the reaction proceeds, entropy increases as the energy stored in the dry wood and leaves are used up as fuel to create the fire which produces low quality light and warmth.
2. This reaction is a classic example of an exothermic reaction. Exothermic reactions are characterized with the presence of heat and light in the products. Combustion reactions are always exothermic in nature.
3. Catalyst are substances that are used to speed up reactions by lowering the activation requirement. Catalysts aren't consumed in the reaction and can still be chemically retrieved afterwards. In this situation, the leaves cannot be retrieved after the reaction ends. The leaves speed up the heating of the wood but it does not behave as a catalyst.
