Answer:
a) 
b) 
Explanation:
Given:
String vibrates transversely fourth dynamic, thus n = 4
mass of the string, m = 13.7 g = 13.7 × 10⁻¹³ kg
Tension in the string, T = 8.39 N
Length of the string, L = 1.87 m
a) we know
where,
= wavelength
on substituting the values, we get
or
b) Speed of the wave (v) in the string is given as:
also,
equating both the formula for 'v' we get,
on substituting the values, we get
or
or
There are some missing information in the question.
However, since you are talking about magnetic force, I think you refer to the Lorentz force. When a particle of charge q and velocity v is immersed in a magnetic field of intensity B, the force acting on the particle is:
where
is the angle between the magnetic field and the direction of the particle.
Therefore, if force F is doubled, then also the velocity v must be double of its initial value:
Answer: Point A is the answer for the potential energy. Point D is the answer for the kinetic energy.
Explanation:
Exert force upward.
Like when you pick something up from the floor, or walk up the stairs.
