Question

Hot air balloon A is rising upward at a rate of 10.0 m/s. A passenger aboard balloon A observes balloon B going down at a relative rate of 12.5 m/s. What is the velocity of balloon B relative to the ground? Assume that up is positive.

Answer 1

@bennyboy489

Answer 2

wouldnt it be -12.5ms? if its relative to the ground and up is positive, and its decending

Answer 3

but there is not -12.5m/s as an option

Answer 4

2.5 m/s
-22.5 m/s
-2.5 m/s
22.5 m/s

Answer 5

but its relative to the ground, not balloon a? are you sure you have the question correct

Answer 6

if it is relative to balloon a, it would be -22.5ms

Answer 7

yea i was going for that one :D thank you !

Answer 8

it would be -2.5 m/sec
the balloon a have velocity w.r.t ground = +10m/sec
the balloon B have velocity w.r.t A = - 12.5m/sec

the velocity of B w.r.t ground = 10 - 12.5 = -2.5 m/sec

means balloon B is decending with velocity 2.5 m/sec relative to ground

Answer 9

but no, because balloon A doesnt come into it, relative to the ground, balloon b is descending at -12.5ms, it is only between balloon B and the ground

Answer 10

let me give you an example
let u abroad a train which is standing on the platform and other train is also at rest parallel to you
now your train start moving with a velocity of 10 m/sec in forward direction and you look at the other train what will you observe that the other train is moving with velocity of 10m/sec in backward direction, but that is at rest w.r.t ground
what if the other train start moving with a velocity of 2.5 m/s in backward direction w.r.t ground
you will observe that the train is moving with velocity 12.5 m/sec in backward direction w.r.t you
but w.r.t ground it is 2.5 m/sec