Q: (1)v=? (2)W=？
Solution:
(1) The length of the teaching building is: s=n? S0=84×0.5m=42m The walking speed of floret is: V = ST = 42m35s =1.2m/s;
(2) In a right triangle,
∫a2+B2 = C2
∴ Height of gravity rising h=65cm-652? 252cm = 5cm = 0.05m
The work done to overcome gravity is w = GH = mgh = 50kg×10n/kg× 0.05m = 25j. .
Answer: (1) The walking speed of floret is1.2m/s;
(2) The work done by overcoming gravity when walking is 25J. ..