Which of these is an indication that a chemical reaction has occurred?

1) melting of a substance

2) boiling of a substance

3) formation of a precipitate

4) freezing of a substance

3 - (a) What is the period of rotation of Earth in seconds? (b) What is the angular velocity of Earth? (c) Given that Earth has a radius of 40,075 km at its equator, what is the linear velocity at Earth's surface?

A forcue of 186 N acts on a 7.3-kg bowling ball for 0.40 s. what is the chanhe in velocity of the bowling ball

Find the interest. A 105-day note for $14,200 at 8.5% interest.

A vessel at rest at the origin of an xy coordinate system explodes into three pieces. Just after the explosion, one piece, of mass m, moves with velocity (-31 m/s) i and a second piece, also of mass m, moves with velocity (-31 m/s) j.

A narrow beam of light containing orange (610 nm) and blue (470 nm) wavelengths goes from polystyrene to air, striking the surface at a 28.5° incident angle. What is the angle (in degrees) between the colors when they emerge?

Modern oil tankers weigh over a half-million tons and have lengths of up to a quarter of a mile. Such massive ships require a distance of 5.0 km (about 3.0 mi) and a time of 22 min to come to a stop from a top speed of 26 km/h.

Suppose a yo-yo has a center shaft that has a 0.232 cm radius and that its string is being pulled. If the string is stationary and the yo-yo accelerates away from it at a rate of 1.50 m/s 2, what is the angular acceleration of the yo-yo?

How far into editing our human genes?

Which electromagnetic wave has the shortest wavelength? (A. Radio waves b. X-rays c. infrared rays or d. Visible light)

Which mixture can be separated based on differences in particle size of the components