Answer : B) The cow pulls back on the girl.
From newton’s third law we know that every action has a reaction force pushing back. So when the girl pulls on a cow, the cow is pulling back on her.
Answer: 62 μT
Explanation:
Given
Length of rod, l = 1.33 m
Velocity of rod, v = 3.19 m/s
Induced emf, e = 0.263*10^-3 V
Using Faraday's law, the induced emf of a rod can be gotten by the formula
e = blv where,
e = induced emf of the rod
b = magnetic field of the rod
l = length of the rod
v = velocity of the rod. On substituting, we have
0.263*10^-3 = b * 1.33 * 3.19
0.263*10^-3 = b * 4.2427
b = 0.263*10^-3 / 4.2427
b = 0.0000620 T
b = 62 μT
Thus, the strength of the magnetic field is 62 μT
Answer:
Explanation: Two pith ball will repel each other . they will remain balaced due to tension in the spring whose one component balances the weight and the other balances the repulsive force on each.
The gravitational force will be balanced by T cos 27.33 and the electrostatic repulsive force will be balanced by T sin27.33
So
Fg =T cos 27.33
= .55 X .888
= .49 N
Fq = T sin27.33
=.55 x .459
= .25 N.
I attached the full question.
We need to calculate the enthalpy change first:

Keep in mind this is the energy per mole, we need energy per atom:

We can see that this reaction needs the energy to get started (enthalpy change is positive).
The energy of a photon is given with this formula:

We need this photon to have the same energy (or higher) as our enthalpy change:

This wavelenght is clasified as near infrared.