All categories

4 years ago

A magnet is passed back and forth through a coil connected to a light bulb. The light bulb lights up. Why?

Physics

2 answers:

Alenkasestr [34]4 years ago

7 0

Answer:

From Faraday's law of Induction: A changing magnetic field induces emf in the coil.

Explanation:

Faraday's law states that when a coil is run through a changing magnetic field or a magnet is passed back and forth through a coil, an emf is induced which produces electric current in the coil.

Changing magnetic flux induces electromotive force.

$e = - \frac{d\phi}{dt} = -\frac{dB A}{dt}$

When the magnet is passed back and forth, it causes a changing magnetic flux around the coil. This induces emf and the current flows which lights up the bulb connected to it.

sdas [7]4 years ago

6 0

The moving back and forth of the magnetic causes a changing magnetic field, which induces an Emf through the coils of the wire and so the bulb ligts up.

You might be interested in

Friction always acts____ and in the ____ direction of the motion of an object

Fed [463]

Answer:

Friction force always acts tangent to the surface at points of contact. Friction force acts opposite to the direction of motion. There are 2 types of friction: Static friction: If the two surfaces in contact do not move relative to each other, one has static friction.

5 0

3 years ago

Parallel to the handle, what is the force of friction acting on the suitcase?

mrs_skeptik [129]

Lets call F the friction force which will act horizontally backwards.

As you are travelling at a constant velosity horizontally there is no overall resultant force in this direction.

ie. the force you pull with will be equal to the friction force resisting you. (you will initially have to have pulled with a greater force than the friction to get the suitcase moving)

the value of your force pulling is 60 cos26.9 (horizontally) - you should have learnt about resolving forces.

this must be equal to F

so

F=60cos26.9
F=53.5N

hope this helps you
please mark this as brainliest answer

5 0

3 years ago

problems like this A diver bounces straight up from a diving board, avoiding the diving board on the way down, and falls feet fi

Ymorist [56]

This question is incomplete the complete question is

A diver bounces straight up from a diving board, avoiding the diving board on the way down, and falls feet first into a pool. She starts with a velocity of 4.00 m/s and her takeoff point is 1.80 m above the pool. (a) What is her highest point above the board? (b) How long a time are her feet in the air? (c) What is her velocity when her feet hit the water?

Answer:

(a) Xs=0.459m

(b) t=0.984 s

Explanation:

(a) To reach maximum distance

$g=-9.8m/s^{2}\\ Vf=0\\v_{b}^{2}=v_{a}^{2}+2gx_{s} \\ x_{s}=\frac{0-(3^{2} )}{-2*9.8}\\ x_{s}=0.459m$

(b) For Time

To find t we must find t1 and t2

t=t1+t2

For T1

$t_{1}=(Vb-Va)/g \\t_{1}=(0-3)/9.8\\t_{1}=0.306s$

For T2

$x_{l}=Vbt+(1/2)gt_{2}^{2}\\ as\\x_{l}=x_{1}+x_{s}\\x_{l}=1.8+0.459\\x_{l}=2.259\\so\\t_{2}=\frac{2.259*2}{9.8} \\t_{2}=0.6789s$

For Total Time

t=t1+t2

t=0.306+0.6789

t=0.984s

(c) To find Vc

Vc=Vb+gt2

Vc=(0)+(9.8)(0.6789)

Vc=6.65 m/s

7 0

3 years ago

Why is it important to keep the muzzle of a firearm pointed in a safe direction, even though the firearm's safety is engaged?

Gnom [1K]

The correct answer is B. The safety only prevents you from pulling the trigger, but does not stop the pin from striking the primer. For example, if you drop the firearm, the pin may hit the primer and fire the firearm. It is always responsible to keep the firearm pointed in a safe direction so that if this happens, no consequences come out of it.

6 0

3 years ago

A 45.0-kg girl is standing on a 168-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat,

muminat

Answer:

The speed of the plank relative to the ice is:

$v_{p}=-0.33\: m/s$