Which of these is an example of a chemical change?

Question 4 options:

fireworks exploding

grinding powder

melting cheese

ironing a shirt

Which statement best describes why a machine is useful?

Two similar metal spheres, A and B, have charges of + 2.0 x10 - 6 coulomb and + 1.0 x10 - 6 coulomb, respectively, as shown in the diagram below. What is the charge on each sphere after the spheres make contact and are then separated?

Who said "give me a place to stand and a long enough lever and I can move the world"?

A toy race car travels down a 25cm ramp in 5 seconds. Calculate its speed. A. 125 cm/sec B. 5 cm/sec C. 0.2 cm/sec D. 20 cm/sec

Can you get sunburned through glass?

HOw are ferns and trees alike and different and what would survive longer without rain fern or tree

1. Using Pj = e^-BE/Z in the Gibb's form for the entropy, show that F = kb Tln (Z), where F = U - TS is the Helmholtz free energy. Here Z= e^-BE is the canonical partition function ...

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?