A ball is thrown at a wall with a velocity of 5 m/s and bounces off at 4 m/s as shown in the diagram. If the impulse provided by the wall is 3 N'm, then what is the mass of the ball?
0.33 kg
60 kg
27 kg
3 kg

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?

When using the scientist method, which step comes last?