7.89•10 to the third power
Answer:
1)
Force on bar magnet = 0
Torque on bar magnet = 0
2)
Force on bar magnet = 0
Torque on bar magnet = 0.177 Nm
3)
Force on bar magnet = 0
Torque on bar magnet = 0.25 Nm
Explanation:
Part 1)
net force on bar magnet in uniform magnetic field is always zero
Torque on bar magnet is given as

when bar magnet is inclined along z axis along magnetic field
then we will have

Part 2)
net force on bar magnet in uniform magnetic field is always zero
Torque on bar magnet is given as

when bar magnet is pointing 45 degree with z axis then we will have



Part 3)
net force on bar magnet in uniform magnetic field is always zero
Torque on bar magnet is given as

when bar magnet is pointing 90 degree with z axis then we will have



Answer:
A) receding from the earth
B) 
Explanation:
- A) receding from the earth
The wavelength went from 434.1nm to 438.6nm, there was an increase in wavelength (also knowecn as redshift due to the doppler efft), this increase is due to the fact that the source that emits the radiation (the distant galaxy) is moving away and therefore the light waves it emits are "stretched", causing us to see a wavelength greater than the original.
- B)

to calculate the relative speed we use the following formula:

where
is the speed of light:
is the wavelength emited by the source, and
is the wavelength measured on earth.
we substitute all the values and do the calculations:

the relative speed is: 
Fnet = -25N + 30N = 5N
(25N is negative since left is negative)