Observations indicate that galaxies with more massive central black holes tend to also have:
1. a greater overall luminosity.
2. a greater mass of stars in their central bulges.
3. a more elliptical shape.

How are positive ions different from neutral atoms

Hello i am required to make a physics experiment plus powerpoint presentation. i want to see your suggestions about simple topics with examples of how to talk about it in the presentation. note: any incomplete answer will be reported.

Atruck going 15 kmôź°€h has a head-on collision with a small car going 30 kmôź°€h. which statement best describes the situation? (a) the truck has the greater change of momentum because it has the greater mass. (b) the car has the greater change of momentum because it has the greater speed. (c) neither the car nor the truck changes its momentum in the collision because momentum is conserved. (d) they both have the same change in magnitude of momentum because momentum is conserved. (e) none of the above is necessarily true. 2. a small boat coasts at constant speed under a bridge. a heavy sack of sand is dropped from the bridge onto the boat. the speed of the boat (a) increases. (b) decreases. (c) does not change. (d) without knowing the mass of the boat and the sand, we can’t tell.