Two trains of distance 100 km travelling towards each other at train a at 60 km/hr and train b at 40km/hr when a bird sitting on train a goes at a speed of 90km/hr starts moving towards train b from train a starts and comes back and forth. find the total distance travelled by the bird

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? )

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

An ionic compound can conduct electricity when a it is dissolved in water b its crystals are ground into powder c it is in solid form d it is heated to just below its melting point