x velocity = 15 across
y velocity = .9 downstream
note order of answers
c. time to cross = 500/15 = 33.33 seconds
b. downstream y = .9 * 33.33 = 30 meters
a. sqrt (.9^2+15^2)
angle to x axis = A = tan^-1(.9/15)
d. sin^-1 (.9/15) toward upstream
e. component of speed across = 15 cos(angle from part d)
then
time = 500/that component
A boat has a speed of 15ms-1 in still water. It is used to cross a river 500m wide along which there is a strong current of 0.9ms-1. The boat is being directed to the opposite bank, but is carried downstream.
Calculate:
a) The boat velocity relative to the bank
b) The distance the boat is carried downstream
c) The time taken to cross
d) The direction the boat must take, relative to the water if it is to cross directly
e) The time taken to cross directly, if it took the direction you calculated in part b.
Solutions would be a massive help guys. Cheers.
1 answer