Q1
Three people set out from the same location on a Sunday morning for a stroll/joy.
John heads north at 9.30 km/h,
Sally heads east at 6.90 km/h and
Joanna heads south at 4.47 km/h.
1a) What is the relative velocity of John as measured by Joanna?__km/h
1b) In what direction?
West
North
East
South
1c) What is the relative velocity of John as measured by Sally?__km/h
1d)At what angle? (between 0° and 90°, this needs to make sense with the next part)
__°
1e) In what direction?
Select one:
North of west
South of east
South of west
North of east
1f) What is the relative velocity of Sally to Joanna?___km/h
1g)At what angle? (between 0° and 90°)__°
1h) In what direction?
South of West
North of East
North of West
South of East
Q2
http://postimg.org/image/hnedwnbtt/
2a)The illustrated pulse travels along the rope towards a metal ring slipped over a pole. It is reflected back along the rope. The rope has a density of 50.0 g/m. The tension in the rope is initially 6287 N. The pulse has a length l = 8.29 cm. The point A on the top is d = 2.61 m from the pole.
How long does it take the pulse to travel from point A to the pole and back to A?__s
2b) Which of the following diagrams correctly illustrates the reflected pulse?
http://postimg.org/image/q5xrxtob3/
2c) The tension is increased to 11243 N. What is the length of the pulse now?__cm
更新1:
謝謝你~~答案全對呀~~不過還有一題好似遺漏了~~~~~~ 2c) The tension is increased to 11243 N. What is the length of the pulse now?__cm