Explain why an experiment should test only one variable at a time

A playground merry-go-round has radius 2.40 m and moment of inertia 2100 kgm2 about a vertical axle through its center, and it turns with negligible friction. (a) A child applies an 18.0-N force tangentially to the edge of the merry-go-round for 15.

A pumper is supplying a 400-foot hoseline with 120 gpm flowing. The hoseline is composed of 250 feet of 2½-inch hose reduced to 150 feet of 1½-inch hose.

Given the electric flux density, D=0.3r^2 ar nC/m^2 infree space, find total charge wothin the sphere r=3

Which of the following materials would generate the strongest magnetic field if used as the core? silicon plastic carbon iron

6. How did a change in voltage affect the use of an electromagnet?

Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer space. They suddenly push each other apart. How far has the heavier astronaut moved when the lighter astronaut has moved 12 m

A person suffering from anaemia gets tired

Jessica took a Mylar balloon outside on a very hot day. As she waited for the bus the balloon began to get bigger. What is the best explanation of this?

Describe how electricity flows through a simple closed circuit.

Solar energy is produced by A. fusion of light nuclei to make heavier ones B. the slow release of heat left over from the Sun's formation C. fission of heavy nuclei into lighter ones D. solar magnetism