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

Find the acceleration that can result from a net force of 20 N exerted on a 2.8-kg

Craig is modeling the discovery of electromagnetism Which procedure should he use? A) moving a magnet into a coil of wire in a closed circuit. B) moving a magnet into a coil of wire in a open circuit.

Find the product. If the result is negative, enter "-". If the result is positive, leave the box empty. 7 (-a^2) ^2 (-b^3)

Hockey ball of mass 200 gram travelling at 10 metre per second is struck by hockey stick. So as to return it along its original path with a velocity at 5 metre per second calculate the magnitude of change of momentum occurred in the motion of the

What are Ultrasonic Waves used for?

Which of the following statements is true? A. Both chemical reaction rates and nuclear decay rates vary with the conditions of the reaction. B. Nuclear decay rates vary with the conditions of the reaction, but chemical reaction rates do not. C.

A star may form a black hole once it cannot?

Kai was 200 meters north of the library when he remembered he had to return some books to the library. It took him 200 seconds to do the round trip. Which best describes Kai's roundtrip?

The engine that powers a crane burns fuel at a temperature of 1500 oC. It is cooled by air at a temperature of 20 oC. The crane is used to lift a 1000 kg steel girder 30 m into the air.

The portion of a light ray that falls on a surface is a/an