Two questions worth 14 points(gradpoint)
1. pu-239 has a half-life of

240 years
24 years
24,000 years
2,400 years
2. nuclear fusion has not yet been harnessed as an energy source because

sufficient pressure cannot be generated
lasers are too dangerous
of a lack of deuterium
the energy is hard to control

State the right hand rule of the direction of magnetic field in a conductor carrying current

Select the word from the list that best fits the definition classification of most stars on the h-r diagram

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?