A piece of copper metal is initially at 100º C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20.0º C. After stirring, the final temperature of both copper and water is 25.0º C. Assuming no heat losses, and that the specific heat (capacity) of water is 4.184 J(g•K), what is the heat capacity of the copper in J/K?
a. 2.79 J/K
b. 3.33 J/K
c. 13.9 J/K
d. 209 J/K
e. none of the above

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied