Which of these describes an exothermic reaction?

1. energy is released by the reaction

2. energy is absorbed by the reaction

3. no energy is transferred by the reaction

4. energy is created in the reaction

A rock is dropped from a third story window to the ground below. Assuming air resistance can be ignored, as it falls: a) only its kinetic energy is conserved. b) only its momentum is conserved.

A solid metal ball is thrown directly downward, with an initial speed of 8.55 m/s, from the top of a structure at a height of 30.6 m. How much time (in s) does it take before striking the ground?

The hormone glucagon is released by number of different tissues in the body to stabilize blood glucose levels.

A rectangular trough, 1.6 m long, 0.50 m wide, and 0.45 m deep, is completely full of water. One end of the trough has a small drain plug right at the bottom edge. Part A When you pull the plug, at what speed does water emerge from the hole

Three identical satellites, X, Y, and Z are in outer space. The distance from satellite X to Y is 450 km, the distance from Y to Z is 600 km, and the distance from satellite Z to X is 450 km.

Which represents a system that is almost completely closed?

If many household substances classify as acids or bases what is the ph scale

A protostar forms once the nebular cloud condenses and the core begins

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are

How much force would be needed to move a car with the mass of 100kg to an acceleration of 5m/s/s?