What is a controlled experiment? none of the variables are changed all variables are kept constant two variables are changed at a time one variable is changed at a time

Critical mass is the ___ of material required to produce a chain reaction. A.) minimum amount B.) atomic mass C.) precise amount D.) maximum amount

The number of protons in the nucleus is also the what?

What is the voltage in a circuit with a resistance of 12 ohms and a current of 20 amp?

If you have a temporary illness that may affect your ability to drive, you should: A. Determine your own fitness for driving B. Obtain a restricted drivers license C. Only drive when you're heavily medicated

A 15 kg child experiences an acceleration of 0.25 m/s2 as she is pulled 1.7 m horizontally across the floor by her sister. what is the change in the child's kinetic energy?

Jane and John Doppler effect

If you combine 430.0 ml of water at 25.00 °c and 140.0 ml of water at 95.00 °c, what is the final temperature of the mixture? use 1.00 g/ml as the density of water. s

While working out, a man performed 200 j of work in 3 seconds. What was his power?

A funnel-shaped low pressure closure

A rubber rod can be charged negatively when it is rubbed with wool. predict what happens when you rub a copper rod with wool