Question1

Astronomers detect a large asteroid that far away but still heading toward earth at 754 m/s. A straight trajectory would bring it within 3.3 x 10^8 of the earth. Though, the earth's gravitational attraction will pull it closer toward earth. Is there cause for alarm?

Question2

A 75.0 kg man, who is engaged in light activity and who is not sweating, uses internal energy at a rate of 200 kcal/h. The man then begins strenuous exercise; requiring 700 kcal/h. assuming that extra heat produced is dissipated throughout sweating and that 25 percent of the sweat evaporates, find the man's rate of sweat production in L/h.

Question3

What mass (in grams) of steam at 100 C have to be mixed with 319 g of ice at its melting point, in a thermally insulated container, to create liquid water at 57.0 C? The particular heat of water is 4186 J/kg K. The latent heat of fusion is 333 kJ/kg, and latent heat of vaporization is 2256 kJ/kg.