A car starts from rest and drives at 45 m/s in 20 s. how far did it travel
1 answer:
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Answer:
Mass of the aluminium chunk = 278.51 g
Explanation:
For an isolated system as given the energy lost and gains in the system will be zero therefore sum of all transfer of energy will be zero,as the temperature will also remain same
A specific heat formula is given as
Energy Change = Mass of liquid x Specific Heat Capacity x Change in temperature
Q = m×c×ΔT
Heat gain by aluminium + heat lost by copper = 0 (1)
For Aluminium:
Q =
Q = m x 17.94 joule
For Copper:
Q= 4996.53 Joule
from eq 1
m x 17.94 = 4996.53
Mass of the aluminium chunk = 278.51 g
There are two conditions necessary for total internal reflection, which is when light hits the boundary between two mediums and reflects back into its original medium:
Light is about to pass from a more optically dense medium (slower) to a less optically dense medium (faster).
The angle of incidence is greater than the defined critical angle for the two mediums, which is given by:
θ = sin⁻¹(/
)
Where θ = critical angle, = refractive index of faster medium,
= refractive index of slower medium.
Choice C gives one of the above necessary conditions.