Answer:
Devices that convert mechanical energy to electric energy. ... An electric generator is a device that changes kinetic energy to electrical energy through electromagnetic induction. ... [Figure1]. Q: What might happen to the current produced by an electric generator if the poles of the magnet kept reversing?
Explanation:
Answer:
1. 571.43m/s
2. 142.9m and 342.9m
Explanation:
1.Take the difference in time.
1.2-0.7=0.7 seconds
Take the distance between them and divide with differnce in time.
400÷0.7=571.43 seconds.
2.Take the time of the two men and divide by two.
0.5÷2= 0.25 secs
1.2÷2= 0.6 secs
multiply each with the velocity.
0.25×571.43=142.9m
0.6×571.43=342.9m
Answer:
Option B and Option D are true
Explanation:
We are given;
Number of atoms in block A = 800
Energy content in block A = 20 quanta
Number of atoms in block B = 200
Energy content in block B = 80 quanta
The energy of a system which is an extensive quantity,depends on the mass or number of moles of the system. However, at equilibrium, the energy density of the two copper blocks will be equal. That is, each atom of Cu in the two blocks will, on average, have the same energy. Because block A has 4 times more atoms than block B, it will have 4 times more quanta of energy. Thus, option B is therefore true while option A is false.
Temperature is a measure of the average kinetic energy of the atoms in a material. Now, if each atom in blocks A and B have the same average energy, then the temperatures of blocks A and B will be equal at equilibrium. Thus, option D is true.
Entropy of a system is an extensive quantity that depends on the the mass or number of atoms in the system. Because block A is bigger than block B, it will have higher entropy. However, that the specific entropy (the entropy per mole or per unit mass) is an intensive quantity -- it is independent of the size of a system. The molar entropy of blocks A and B are equal at equilibrium. Thus option C is false.
Well you of course have different kinetic energies with the two speeds.
Kinetic energy = (1/2)*mass*velocity^2
The vehicle's mass is the same in both cases, so we can ignore that as well as 1/2 since it's a constant.
So we have (30)^2 vs (60^2)
which is 900 vs 3600
So having 60 mph compared to 30 mph is 4 times the kinetic energy.
