(89000/102000)×100
=87.25%
(92000/104000)×100
=88.46%
efficiency is (output/input)×100
if u get confused which way input and output should go, remember the smaller value is always output and it's above in the fraction, then only it's possible to get a efficiency lower than 100.
Answer:
Explanation:
the center of mass formula
Ycm= [(m₁y₁) + (m₂y₂) + (m₃y₃)] / (m₁+m₂+m₃)
Rope forms the x axis and position of centre of different massses are above or below it so they represent their location on y - axis.
y₁ = 1.6 , y₂ = .7 and y₃ = - 2.1
Ycm ( given ) = - .5
Putting the values of masses and positions
- .5 = 80 x 1.6 + 20 x .7 + m₃ x - 2.1 / ( 80 + 20 + m₃ )
- .5 = 128 + 14 + m₃ x - 2.1 / ( 100+ m₃ )
- 50 - .5 m₃ = 142 - 2.1 m₃
1.6 m₃ = 192
m₃ = 120 kg .
B )
Total downward force is weight of total mass = 80 + 20 + 120
= 220 kg
weight = 220 x 9.8 = 2156 N .
component of weight perpendicular to rope
= 2156 cos 15 = 2082.53 N
This force will be equally distributed over each tree , so force on each tree = 2082.53 / 2 = 1041.26 N .
When it comes to optics, Snell's law is the basic formula to be used. If you notice, when light hits the water, the light does not travel in the same direction. After, it hits the water, it changes in angle. Light becomes refracted. This is observed when your hands tend to become bigger if you place it underwater. The formula for Snell's Law is
n₁ sin θ₁ = n₂sin θ₂, where n is the index of refraction. This depends on the type of medium. For example, for air, n=1. The parameters θ₁ is the angle of incidence, and θ₂ is the angle of refraction. Critical angle is the incident angle needed so that the refract angle is 90°. So, modifying the equation:
n₁ sin θcrit = n₂sin 90°, since sin 90°=1,
sin θcrit = n₂/n₁
θcrit = sin ⁻¹ (n₂/n₁)
Since liquid comes first before glass, n₁=1.75 and n₂=1.52. Substituting,
θcrit = sin ⁻¹ (1.52/1.75)
θcrit = 60.29°
Answer:
instantaneous velocity is a velocity covered at an instant while average velocity is the change in distance/ the change in time taken
