Question

18)An airplane has to fly eastward to a destination 856 km away. If wind is blowing at 18.0 m/s northward and the air speed of the plane is 161 m/s, in what direction should the plane head to reach its destination?

6.42 degrees south of east

19)A 4400 kg can accelerate from 0-25m/s in 4 seconds. What force must the engine create to accomplish this acceleration?

I don't know

20)An elevator is moving up with an acceleration of 3.36 m/s^2. What would be the apparent weight of a 64.2 kg man in the elevator?

I don't know

Answer 1

8)An airplane has to fly eastward to a destination 856 km away. If wind is blowing at 18.0 m/s northward and the air speed of the plane is 161 m/s, in what direction should the plane head to reach its destination?
===================

The 856 km has nothing to do with it. The point is - fly east.
North components come out to zero
18 - 161 sin(angle south of east) = 0
sin angle = .112
angle = 6.42 check


6.42 degrees south of east

19)A 4400 kg can accelerate from 0-25m/s in 4 seconds. What force must the engine create to accomplish this acceleration?

I don't know
==
F = m a
a = 25/m/s / 4 s = 6.25 m/s^2
F = 4400 * 6.25

20)An elevator is moving up with an acceleration of 3.36 m/s^2. What would be the apparent weight of a 64.2 kg man in the elevator?

I don't know
=
F = ma
Force up from elevator on man - weight of man = mass * a
F - m (9.8) = m (3.36)
F = 64.2 * (13.2)

Answer 2

ok I got 847.44 for #20 but that's not one of my choices. they are: 215.71, 413.45, 844.87, and need more info

Answer 3

I agree with you, 847 N