Answer:
A north magnet attracts a south magnet
Explanation:
The opposite polar magnetic field will attract each other while the same polar magnetic fields will repel each other.
Answer:
Yes, it would work.
Explanation:
From Flehmings left hand rule, current can be generated when a coil cuts the magnetic field of a powerful magnet. Thus, the spin of properller turns a generator thereby converts motion to electrical energy.
The major challenge would be how to set the car in motion when at rest. But this can be solved by energy consrvation process. The law of conservation of energy states that energy cannot be created or destoyed, but transformed from one form to another. Thus, there would be mechanism having a device called an inverter which stores electric energy when the vehicle is in motion. This regenerates the required initial energy to set the electric car in motion when at rest or stops.
Answer:
D- Only the 2nd law of thermodynamics
Explanation:
It violates 2nd law because according to 2nd law of thermodynamics, it is impossible that the sole result of a process is is to absorb energy and do equivalent amount of work. so some heat must lose to surrounding which is not specified here. so it violates 2nd law.
so option D is correct
These are two questions and two answers.
Part 1. Fin the value of the ration of velocity C to velocity D.
Answer: 2
Explanation:
1) Formula: momentum = mass * velocity
2) momentum C = mass C * velocity C
3) momentum D = mass D * velocity D.
4) C and D have the same momentum =>
mass C * velocity C = mass D * velocity D
5) mass C = (1/2) mass D => mass C / mass C = 1/2
6) use in the equation stated in the point 4)
velocit C / velocity D = mass D / mass C
using the equation stated in point 5:
mass D / mass C = 1 / [ mass C / mass D] = 1 / [1/2] = 2
=>
7) velocity C / velocity D = mass D / mass C = 2
Part 2: <span>ratio of kinetic energy C to kinetic energy D.
</span>
Answer: 2
Explanation:
1) formula: kinetic energy KE = (1/2) mass * (velocity)^2
2) KE C = (1/2) mass C * (velocity C)^2
3) KE D = (1/2) mass D * (velocity D)^2
4) KE C / KE D =
(1/2) mass C * (velocity C)^2 mass C (velocity C)^2
--------------------------------------- = --------------- * ---------------------- = (1/2) * (2)^2
(1/2) mass D *( velocity D)^2 mass D v(velocity D)^2
= 4 / 2 = 2
Period T = 1/f, where f = frequency = 5 Hz
T = 1/5 = 0.20 s
Period = 0.20 seconds.
