Answer:
The lenses with different focal length are four.
Explanation:
Given that,
Radius of curvature R₁= 4
Radius of curvature R₂ = 8
We know ,
Refractive index of glass = 1.6
When, R₁= 4, R₂ = 8
We need to calculate the focal length of the lens
Using formula of focal length

Put the value into the formula



When , R₁= -4, R₂ = 8
Put the value into the formula



When , R₁= 4, R₂ = -8
Put the value into the formula



When , R₁= -4, R₂ = -8
Put the value into the formula



Hence, The lenses with different focal length are four.
P = m*v
7.5 = m*15
m = 7.5/15 = 0.5 kg
To solve this problem we will apply the theorem given in the conservation of energy, by which we have that it is conserved and that in terms of potential and kinetic energy, in their initial moment they must be equal to the final potential and kinetic energy. This is,


Replacing the 5100MJ for satellite as initial potential energy, 4200MJ for initial kinetic energy and 5700MJ for final potential energy we have that



Therefore the final kinetic energy is 3600MJ
Answer
Given,
Average speed of Malcolm and Ravi = 260 km/h
Let speed of the Malcolm be X and speed of the Ravi Y.
From the given statement

....(i)
....(ii)
Adding both the equations
3 X = 600
X = 200 km/h
Putting value in equation (i)
Y = 520 - 200
Y = 320 Km/h
Speed of Malcolm = 200 Km/h
Speed of Ravi = 320 Km/h
Wind Energy is the kind of energy will Cassie uses to power the boat.
What is wind energy?
The method of producing electricity using air or wind currents that naturally occur in the earth's atmosphere is known as wind energy (or wind power). Electricity is produced by modern wind turbines that harness the kinetic energy of the wind. Wind passing across the turbine's blades is the initial step.
What is the major problem with wind energy?
Wind energy has the potential to have negative environmental effects, including the possibility of reducing, fragmenting, or deteriorating habitat for wildlife, fish, and plants, as with all energy supply choices. Furthermore, flying animals like birds and bats may be harmed by turbine blades in operation.
Learn more about wind energy: brainly.com/question/27997211
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