Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
Answer:
As the temperature increases, the kinetic energy of the particles increases.
Explanation:
When the temperature of the substance increases, the velocity increases which makes the movement of the particles to speed up. This causes the particles to increase. Therefore, as the temperature increases, the kinetic energy of the particles also increases.
Answer:
True
Explanation:
Because in atom the negative charge become lose or gain.
Answer:
I'm not sure if I know whatever the answer is
There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:

- radius of the hill:

Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car

(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,

, so we can write:

(1)
By rearranging the equation and substituting the numbers, we find N:

(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:

(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:

from which we find