Aprimitive space heater consists of a 10.0 cm radius iron ball through which electrical current was passed in order to heat the ball, and subsequently the surrounding air. if the temperature of the iron ball is kept at 510 k, and the room temperature is 20oc, what power is radiated into the room? assume the ball is a perfect blackbody.
a. 110w
b. 480w
c. 140w
d. 430w

Aball bearing at 220.0 °c is dropped into a cup containing 250.0 g of water at 20.0 °c. the water and ball bearing come to a temperature of 30.0 °c. what is the heat capacity of the ball bearing in j/°c? (hint: how are the algebraic signs of q related for the ball bearing and the water? )

What is the rate of 12 liters of water moving through a water hose in 4.0 minutes?

Ablock of mass m slides on a horizontal frictionless table with an initial speed v0 . it then compresses a spring of force constant k and is brought to rest. the acceleration of gravity is 9.8 m/s2. how much is the spring compressed x from its natural length? 1) x = v0*sqrt(k/(mg)) 2) x=v0*sqrt(m/k) 3) x=v0*((mk)/g) 4) x=v0*sqrt(k/m) 5) x=v0*(m/kg) 6) x=v0*sqrt((mg)/k) 7) x=(v0)^2/(2g) 8) x=v0*(k/(mg)) 9) x=(v0)^2/(2m) 10) x=v0*((mg)/k)