Answer:
A. There is a localization of positive charge near the door handle.
Explanation:
- When on a cold morning a person wearing cotton/ polyester cloth walking on the carpet moves toward his car then due to friction between the feet and the carpet there are transfer of electrons from the carpet to our feet, and since our body is a good conductor of electricity the charges spread throughout on the surface of or body.
- When the person brings his hands close to the neutral conducting door of the car it gets induced with equal intensity of opposite charge to our hands thus having a concentration of positive charges near to the hand on the car's door is developed as a result of polarization within the conductor.
The magnetic force experienced by the proton is given by
where q is the proton charge, v its velocity, B the magnitude of the magnetic field and
the angle between the direction of v and B. Since the proton moves perpendicularly to the magnetic field, this angle is 90 degrees, so
and we can ignore it in the formula.
For Netwon's second law, the force is also equal to the proton mass times its acceleration:
So we have
from which we can find the magnitude of the field:
Answer: Speed = 4 m/s
Explanation:
The parameters given are
Mass M = 60 kg
Height h = 0.8 m
Acceleration due to gravity g= 10 m/s2
Before the man jumps, he will be experiencing potential energy at the top of the table.
P.E = mgh
Substitute all the parameters into the formula
P.E = 60 × 9.8 × 0.8
P.E = 470.4 J
As he jumped from the table and hit the ground, the whole P.E will be converted to kinetic energy according to conservative of energy.
When hitting the ground,
K.E = P.E
Where K.E = 1/2mv^2
Substitute m and 470.4 into the formula
470.4 = 1/2 × 60 × V^2
V^2 = 470.4/30
V^2 = 15.68
V = square root (15.68)
V = 3.959 m/s
Therefore, the speed of the man when hitting the ground is approximately 4 m/s
