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:
3.82 ms
Explanation:
The period of a wave is equal to the reciprocal of the frequency:

where f is the frequency.
In this problem, f = 262 Hz, so the period if this sound wave is

Answer:
1.70 J
Explanation:
The heat dissipated is the difference in the kinetic energies.
This is given by

and
are the initial and final velocities.
With <em>m</em> = 0.175 kg,

The negative sign appears because energy is lost.
Answer:
Sunlight passing through a cloud is scattered in various directions. Some photons eventually find their way out the bottom of the cloud, some are reflected upwards, and some are absorbed, serving to warm the cloud. Since only a fraction of the light makes it to ground level, you have a shadow.
Explanation:
Hope it helps you