Question
https MasteringPhysics Ehttps//session.masteringphysics.com/myct/iten myct/iternView?assi 84103869 Norton + Delivering a Package by Air Resources previous | 10 of 10 I return to assignment Part A (Figure 1) A relief airplane is delivering a food package to a group of people stranded on a very small island. The island is too small for the plane to land on, and the only way to deliver the package is by dropping it The airplane flies horizontally with constant speed of 412 km/hour at an altitude of 575 m. The positive x and y directions are defined in the figure. For all parts, assume that the "island refers to the point at a distance D from the point at which the s dropped from the plane, how long wll i take for it to reach sea level from the time it is has an initial velocity of 412 km/hour in the horizontal direction Express your answer numerically in seconds. Neglect air resistance Hints e is released, as shown in the figure Ignore the height of this point above sea level. Assume that v the acceleration due to aravitv is a 9 80 m/s2 613? igure 1 1 of 1 Submit My Answers Sive Up Incorrect; Try Again; 4 attempts remaining t Assignment Part B If the package is to land right on the island, at what horizontal distance D from the plane to the island should the package be released? PHYSCS Express the distance numerically in meters.
Explanation / Answer
(A) horizontal velocity = 412 km/h
= 412 x 1000 m / 3600s
= 114.44 m/s
so initial vertical velocity, v0y = 0
a = - 9.8 m/s^2
Applying y = v0 t + a t^2 /2 in vertical,
- 575 = 0 - 9.8 t^2 / 2
t = 10.8 sec ........Ans
(B) D = v0 t
= 114.44 x 10.8
= 1240 m
(C) vy = 0 - (9.8 x 10.8)
vy = - 105.8 m/s
vx = 114.44 m/s
Speed = sqrt(105.8^2 + 114.44^2)
= 156 m/s
{ 43 deg below the horizontal}
