Why must you repeat steps three and four in the scientific method

15 grams of liquid plastic are frozen in a physical change that increases the volume. What can be known about the plastic after the change?

Explain whether or not a particle would have acceleration if (a) it's moving in a straight line with constant speed, and (b) moving around a curve with constant speed

Clearly, Atwood's machine has a lot of systematic error that would not be present if we were to simplify the experiment.

A boy pedals his bicycle with a net horizontal force of 235 N. If the total mass of the boy and the bike is 40 kg, how much are they accelerating

What is the energy equivalent of 5.0 kg of mass? be sure to show all work to support your answer?

What is the total number of atoms in the following formula? CaBr2 04

The Amazon River is in Europe. True or False

A microwave oven operating at 120 volts is used to heat a sandwich if the oven draws 12.5 amperes of current for 45 seconds what is the power dissipated by the oven?

Which of the transformers are step-up transformers? Which of the transformers are step-down transformers?

1 A plane moving at 30m/s drops a load 200m down to the ground. How long did it take to hit the ground.