Answer:
D
Explanation:
There is a variety of many types of energies. Some of which are mechanical, thermal, electromagnetic, nuclear, chemical, sonic, and more.
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: when a object gets slowed down, it's force is either going into friction and drag, if it's on the ground, and weight+drag+friction, if it's in the air.
Explanation:
The answer is most likely A
The feel of weight comes due to the normal reaction force given by the support. Hence, the condition of weightlessness is when the normal reaction force becomes zero. So, during free fall there is no support which can provide the normal reaction. Hence, the bungee jumper feels weightless as she falls towards the earth because of the lack of support force that balances gravity.
Hence, the answer is 3.
