Answer:
572.3 nm
Explanation:
= refractive index of the oil film = 1.48
= thickness of the oil film = 290 nm
= wavelength of the dominant color
m = order
Using the equation

For m = 0

= 1716.8 nm
For m = 1

= 572.3 nm
For m = 2

= 343.4 nm
Hence the dominant color wavelength is 572.3 nm
The amount of heat given by the water to the block of ice can be calculated by using

where

is the mass of the water

is the specific heat capacity of water

is the variation of temperature of the water.
Using these numbers, we find

This is the amount of heat released by the water, but this is exactly equal to the amount of heat absorbed by the ice, used to melt it into water according to the formula:

where

is the mass of the ice while

is the specific latent heat of fusion of the ice.
Re-arranging this formula and using the heat Q that we found previously, we can calculate the mass of the ice:
Answer:
F = 200 N
Explanation:
Given that,
The mass suspended from the rope, m = 20 kg
We need to find the resultant force acting on the rope. The resultant force on the rope is equal to its weight such that,
F = mg
Where
g is acceleration due to gravity
Put all the values,
F = 20 kg × 10 m/s²
F = 200 N
So, the resultant force on the mass is 200 N.
Answer:
Power input, P = 2880 watts
Explanation:
It is given that,
Voltage of the motor, V = 240 V
Current required, I = 12 A
Weight lifted, W = 2000 lb
It is lifting at a speed of 25 ft/min. We need to find the power input to the motor. The product of current and voltage is called power input of the motor.


P = 2880 watts
So, the power input of the motor is 2880 watts. Hence, this is the required solution.