LiftA= u m/s ( upwards)
LiftB= -u m/s(downward)
Velocity A relative to B= V lift A- V lift B=8m/s
u-(-u)=8
u=4m/s
Lift A= 4 m/sec
Lift B= -4m/sec
For someone standing on first floor will be stationary W.r.t to the lift.
V lift A relative to Man= V liftA - V man= 4m/s
V lift B relative to Man= V lift B- V Man= -4 m/s
Answer:
We have the function:
r = -3 + 4*cos(θ)
And we want to find the value of θ where we have the maximum value of r.
For this, we can see that the cosine function has a positive coeficient, so when the cosine function has a maximum, also does the value of r.
We know that the meaximum value of the cosine is 1, and it happens when:
θ = 2n*pi, for any integer value of n.
Then the answer is θ = 2n*pi, in this point we have:
r = -3 + 4*cos (2n*pi) = -3 + 4 = 1
The maximum value of r is 7
(while you may have a biger, in magnitude, value for r if you select the negative solutions for the cosine, you need to remember that the radius must be always a positive number)
It’s the third graph down!!