Four students run up a flight of stairs. Below are their masses, time it takes t
ID: 2038413 • Letter: F
Question
Four students run up a flight of stairs. Below are their masses, time it takes to run, and the total height of the stairs they run. (Not the length of stairs) Rank in order from smallest to largest, their power outputs : A. 80kg, 8 seconds, 1 flight= 10m B. 64kg, 20 seconds, 3 flight= 30m C. 80kg, 25 seconds, 2 flight= 20 m D. 64kg, 8 seconds, 1 flight= 10m Four students run up a flight of stairs. Below are their masses, time it takes to run, and the total height of the stairs they run. (Not the length of stairs) Rank in order from smallest to largest, their power outputs : A. 80kg, 8 seconds, 1 flight= 10m B. 64kg, 20 seconds, 3 flight= 30m C. 80kg, 25 seconds, 2 flight= 20 m D. 64kg, 8 seconds, 1 flight= 10m Rank in order from smallest to largest, their power outputs : A. 80kg, 8 seconds, 1 flight= 10m B. 64kg, 20 seconds, 3 flight= 30m C. 80kg, 25 seconds, 2 flight= 20 m D. 64kg, 8 seconds, 1 flight= 10mExplanation / Answer
given
the power is P = W/t = mgh /t W
PA = 80*9.8*10 /8 w = 980 W
PB = 64*9.8*30 /20 w = 940.8 W
PC = 80*9.8*20/25 W = 627.20 W
PD = 64*9.8*10/8 W = 784 W
now the ranking from smallest to largest is
Pc < PD < PB < PA