How do you know when water is boiling?

A5 nc point charge is at the origin and a second 3 nc point charge is on the x-axis at x = 0.8 m. find the magnitude and direction of the electric field on the x-axs at x = 0.2 m. you may express the direction by letting positive field mean the positive x direction

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)