Answer:
The doorbell transforms electrical energy into sound.
Explanation:
The doorbell MAY turn electrical energy into motion of a striker which then impacts a resonator creating sound. However all door bells do not have solenoids. Some are electronic playing recordings when activated.
All doorbells do produce sound, though.
Your answer would be D.
If an object has mass, it has gravity, and the more mass it has, the stronger its gravity. During the formation of planets, essentially, various matter and elements pulled and fused together (because of the gravity), forming planetesimals.
Mutation because they change the genes
Answer:
Induced emf in the coil, E = 0.157 volts
Explanation:
It is given that,
Number of turns, N = 100
Diameter of the coil, d = 3 cm = 0.03 m
Radius of the coil, r = 0.015 m
A uniform magnetic field increases from 0.5 T to 2.5 T in 0.9 s.
Due to this change in magnetic field, an emf is induced in the coil which is given by :
E = -0.157 volts
Minus sign shows the direction of induced emf in the coil. Hence, the induced emf in the coil is 0.157 volts.
Answer:
I = 8.75 kg m
Explanation:
This is a rotational movement exercise, let's start with kinetic energy
K = ½ I w²
They tell us that K = 330 J, let's find the angular velocity with kinematics
w² = w₀² + 2 α θ
as part of rest w₀ = 0
w = √ 2α θ
let's reduce the revolutions to the SI system
θ = 30.0 rev (2π rad / 1 rev) = 60π rad
let's calculate the angular velocity
w = √(2 0.200 60π)
w = 8.683 rad / s
we clear from the first equation
I = 2K / w²
let's calculate
I = 2 330 / 8,683²
I = 8.75 kg m
