Ablackened, solid copper sphere of radius 4.00 cm hangs in a vacuum in an enclosure whose walls have a temperature of 20.0°c. if the sphere is initially at 0°c, find the rate at which its temperature changes, assuming that heat is transferred by radiation.

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?

If vx = 7.00 units and vy = -7.60 units, determine the magnitude of v⃗ . determine the direction of v⃗ .

The two required components for a generator are