Answer:1.04 N
Explanation:
Given
Gravitational Force on the Platter is 
Tray makes an angle of 
This gravitational Force has components along and Perpendicular to Platter
Perpendicular Force 

Along the Tray


Thus 1.04 N is the magnitude of force that will cause Platter to slide down
The potential energy decreases while the kinetic energy increases.
Answer:
the inertia provides the tendency to maintain speed and keep moving
We calculate current from the formula:

, where q is a electric charge transferred over time t
Time should be converted to seconds:
1h 15 min= 75min= 4500s
I=

Result is in unit-Ampere
Answer:
1) The medium b has higher optical density.
2) If the optical densities of both A and B are same.
Explanation:
- The refractive index of a material determines the number of times the velocity of light in that material is slower than the velocity of light in a vacuum.
- The higher refractive index means slower propagation of the light in that medium.
- The refractive index of the medium determines the optical density of the medium.
- If the material has a higher refractive index, then its optical density is high.
- If the material has a low refractive index, then its optical density is low.
- The light bends towards the normal while refracting through the medium from a lower optical density medium to the higher optical density medium.
- If both the mediums has the same optical density, the direction of propagation doesn't change.