Because it records speed of the car at a certain time, the independent variable should be time and dependent would be speed or velocity. Since it's taken every second, it would be considered instantaneous velocity, which is D.
Answer:
I think the answer is
C) iron nails are attracted towards all materials
Answer:
B = 4.1*10^-3 T = 4.1mT
Explanation:
In order to calculate the strength of the magnetic field, you use the following formula for the magnetic flux trough a surface:
(1)
ФB: magnetic flux trough the circular surface = 6.80*10^-5 T.m^2
S: surface area of the circular plate = π.r^2
r: radius of the circular plate = 8.50cm = 0.085m
B: magnitude of the magnetic field = ?
α: angle between the direction of the magnetic field and the normal to the surface area of the circular plate = 43.0°
You solve the equation (1) for B, and replace the values of the other parameters:

The strength of the magntetic field is 4.1mT
Answer:
r = 0.22m
Explanation:
To find the radius of the circular trajectory, you first take into account that the centripetal force of the charged particle, is equal to the electric force between the particle that is moving and the particle at the center of the orbit.
Then, you have:
(1)
m: mass of the particle = 20g = 20*10-3 kg
ac: centripetal acceleration = ?
q: charge of the particle = 5*10^-6C
Fe: electric force between the charges
The electric force is given by:
(2)
r: radius of the orbit
q': charge of the particle at the center of the orbit = -5*10^-6C
Furthermore, the centripetal acceleration is:
(3)
v: speed of the particle = 7m/s
You replace the expressions (2) and (3) in the equation (1) and solve for r:

Finally, you replace the values of all parameters in the previous expression:

The radius of the circular trajectory is 0.22m