Answer: D(t)= 50(4/5)^t
Explanation: If 1/5 of the temperature difference is lost each minute, that means 4/5 of the difference remains each minute. So each minute, the temperature difference is multiplied by a factor of 4/5 (or 0.8).
If we start with the initial temperature difference, 50° Celsius, and keep multiplying by 4/5, this function gives us the temperature difference t minutes after the cake was put in the cooler.
To develop this problem it is necessary to apply the concepts related to a magnetic field in spheres.
By definition we know that the magnetic field in a sphere can be described as

Where,
a = Radius
z = Distance to the magnetic field
I = Current
Permeability constant in free space
Our values are given as
diameter of the sphere then,

Thus z = a



Re-arrange to find I,



Therefore the current at the pole of this sphere is 
1,) C
2,) C
Hope this helps
The intaneuos velocity of an object is the
Answer:
upward
4.725 kgm/s to the right
468.6 kgm/s southwest
forward
Explanation:
When the mass of an object is multiplied by its velocity we get momentum
m = Mass
v = Velocity
Proton

The momentum of the proton is
upward
Bullet

The momentum of the bullet is 4.725 kgm/s to the right
Sprinter

The momentum of the sprinter is 468.6 kgm/s southwest
Earth

The momentum of the sprinter is
forward