_____ to be a good swimmer, you should know how to hold your breath for a while.
(a) for while
(b) however since
(c) in place
(d) in order

Write down the part of the sentences that has an error. If there is no error mark (d) as your answer. (a) As your know / (b) that the ignorant / (c ) are easily duped. / (d) No error.

If (A+o+B)^^(~A ThetaB)=A^^B what should be proper symbol in place of o+ and Theta to hold the equation (a) ^^ and vv (b) ^^ and ^^ (c) vv and vv (d) vv and ^^

Four men light a 250 kg box to a height of 1m and hold it without raising or lowering it. (a) How much work is done by the men in lifting the box ? (b) How much work do they do in just holding it ? (c ) why do they get tired while holding it ? (g = 10m//s^2)

If you were to walk brieftly in space without a spacesuit while far from the Sun ( as an astronaut does in the movie 2001, A Space Odyssey ), you would feel the cold of space- while you radiated energy, you would absorb almost non from your environment . (a) At what rate would you lose energy ? (b) How much energy would you lose in 44s ? Assume that your emissivity is 0.90, and estimate other data needed in the calculations.