Problema Solution
A UFO is spotted 920 miles from an airfield, heading towards the field at 430 miles per hour. A jet takes off immediately to intercept the object.
(a) If the jet flies at 750 miles per hour, how long after the initial sighting does the pilot reach the object?
(b) How fast must the jet fly to intercept the object in .60 h?
Answer provided by our tutors
Let
v1 = 430 mph the speed of the UFO
v2 = 750 mph the speed of the jet
d = 920 mi the distance between the UFO and the jet
(a) Let 't' represent the time of the intercept
Since distance = speed*time we have:
v1t + v2t = d
430t + 750t = 920
........
click here to see the equation solved for t
........
t = 46/59 hr
t = (46/59)*60 min
t = 46.8 min
The pilot will reach the object in 46.8 minutes.
(b) Let 'v' represent the speed of the jet.
t = 0.60 hr
vt + v2t = d
0.60v + 0.60*750 = 920
........
click here to see the equations solved for v
........
v = 783.33 mph
The jet must fly with 783.33 mph.