Which of these holds a galaxy together?

A. disk

B. gravity

C. open clusters

D. globular clusters

What produces an electromagnetic wave? A) An oscillating or accelerating electric charge B) An electric charge moving at constant velocity C) A static electric charge D) A magnetic monopole moving at constant velocity

A perfectly elastic collision is a collision: a. Between two springs. b. That conserves thermal energy. c. That conserves kinetic energy. d. That conserves potential energy. e. That conserves mechanical energy.

does increasing the frequency of a wave also increase its wavelength if not how are these quantities related

An internal combustion engine uses fuel, of energy content 44.4 MJ/kg, at a rate of 5kg/h. If the efficiency is 28%, determine the power output and the rate of heat rejection?

If a force of 20 N is applied to an object with a mass of 3 kg, the object will accelerate at m/s2

Which of these best explains why people on Earth cannot see the entire shape of the Milky Way A Earth is a part of this galaxy. B Many more stars exist outside the galaxy. C The stars in the center of the galaxy are extremely small.

4.6 billion years ago, the Earth is created from what

A baseball is hit almost straight up into the air with a speed of 21 m/s. how much time does it take for the package to reach the ground?

Can an object be accelerated without speeding up or slowing down explain by examples

Kenny klutz drops his physics book off his aunt's high-rise balcony. it hits the ground below 1.5 s later? a. with what speed does it hit? b. how high is the balcony? ignore air drag.