Answer: f=150cm in water and f=60cm in air.
Explanation: Focal length is a measurement of how strong light is converged or diverged by a system. To find the variable, it can be used the formula:
= (nglass - ni)(
-
).
nglass is the index of refraction of the glass;
ni is the index of refraction of the medium you want, water in this case;
R1 is the curvature through which light enters the lens;
R2 is the curvature of the surface which it exits the lens;
Substituting and calculating for water (nwater = 1.3):
= (1.5 - 1.3)(
-
)
= 0.2(
)
f =
= 150
For air (nair = 1):
= (1.5 - 1)(
-
)
f =
= 60
In water, the focal length of the lens is f = 150cm.
In air, f = 60cm.
Answer:
v = 2.21 m/s
Explanation:
The foreman had released the box from rest at a height of 0.25 m above the ground.
We need to find the speed of the crate when it reaches the bottom of the ramp. Let v is the velocity at the bottom of the ramp. It can be calculated using conservation of energy as follows :

So, its velocity at the bottom of the ramp is 2.21 m/s.
Answer: Anthony will be warmer after the game.
Explanation :
Anthony and Maelynn are watching a football game outside on a sunny day. Anthony is wearing a black shirt and Maelynn is wearing a white shirt. Anthony will be warmer after the game. The black color is a good absorber of radiation and a bad reflector.
The black color absorbs heat until a thermal equilibrium is attained. So, it is advisable to wear cotton clothes in summers not dark colored clothes.
-3 m/s
---------
per min
oh I think 8m/s to 3m/s to 0m/s
idk probably -0.08
Answer:
Impulse = 90
Resulting Velocity = 89
Explanation:
Use F * change in time = m * change in velocity.
For the first part of the question, the left side of the equation is the impulse. Plug it in.
60 * (3.0 - 0) = 90.
For the second half. we use all parts of the equation. I'm gonna use vf for the final velocity.
60 * (3.0 - 0) = 10 * (vf - 80). Simplify.
90 = 10vf - 800. Simplify again.
890 = 10vf. Divide to simplify and get the answer.
The resulting velocity is 89.