An element's mass number tells the number of protons in its nucleus true or false?

The X-ray source Cygnus X-1 has a mass of at least 11 solar masses and a diameter of only about one-quarter the diameter of the Earth.

What's is the definition of STD

A truck with 0.420 m radius tires travels at 32 m/s. What is the angular velocity of the rotating tires in radians per second? What is the angular velocity of the rotating tires in rev/min?

Why can work be thought of as the transfer of energy

A 100 N force pulls a box horizontally across a floor for 2 m. How much was done by the force of gravity (which pulls straight down on the box) ?

Is a light bulb considered construction

Witch statement about polymers is true

Which safety measures should you follow during a thunderstorm? Check all that apply. (A) Avoid touching anything that conducts electricity. (B) Avoid touching a person who has been struck by lightning. (C) Go outside.

1. An automobile with a mass of 1000 kg accelerates when the traffic light turns green. If the net force on the car is 4000 N, what is the car's acceleration?

Imagine that you replace the block in the video with a happy or sad ball identical to the one used as a pendulum, so that the sad ball strikes a sad ball and the happy ball strikes a happy ball.