Why the efficiency of an engine cannot be 100%?

2 answers:

6 0

<span>No machine can operate at 100 percent efficiency because some of the energy input will always be used to overcome the force of gravity and the effects of friction and air resistance.</span>

Alex73 [517]3 years ago

3 0

No, because the engine can't convert enough heat. 100%? That's way too much. That is theoretically impossible. Its important to consider the equation, this will give you the better picture as to why it can't be. In fact, the maximum efficiency CANNOT be more than the Carnot limit. Its the 2nd Law of Thermodynamics.
nth ≤ 1 - (Tc/Th)

I hope this helped.

You might be interested in

The sun is made up mostly of

mezya [45]

The sun is made mostly up of Hydrogen.

3 0

4 years ago

Read 2 more answers

A block of plastic in the shape of a rectangular solid that has height 8.00 cm and area A for its top and bottom surfaces is flo

kifflom [539]

Answer:

0.35 kg

Explanation:

8 cm = 0.08 m

For the block to stay balance, the buoyancy force must be the same as gravity that pulls it down.

Let mass of the block be M, then the gravity would be Mg

Let water density be $\rho_w = 1000 kg/m^3$ , the buoyancy force would be the weight of water that is displaced by the submerged block.

For example, when there is no coin, block is $h_0 = 0.0312m$ submerged. The weight of water displaced must be

$W_0 = Ah_0\rho_wg = 0.0312A1000g = 31.2Ag$

Which is also the weight of block, of Mg

Therefore M = 31.2A. (1)

As coins are stacked on top of block, h increase, so as weight of water displaced and total weight of block and coins. Now let m be the total weight of coins. The gravity of block and weight must be (M+m)g. And the weight of water displaced is:

$W = Ah\rho g = (M + m)g$