Question

1) A jet aircraft with mass of 386369 kilograms is flying straight upward. At an instant the plane's engine is producing an upward thrust (force) of 7464759 Newtons and air resistance is exerting a force of 90000 Newtons downward. What is the acceleration of the plane in m/s2at that instant?Note: In this problem, we define "up" as positive.

2) A 1094 kilogram truck pulling a 415 kilogram trailer exerts a 2132 Newton force on the road and produces an acceleration of 0.72 meters/second 2. What total force resists the motion of the truck and trailer? Hint: The correct answer is a positive number of Newtons.

Answer 1

1)Mass of aircraft,m= 386369kg downwards

Thrust =7464759 N upwards

Air resistance = 90000N downwards

Net Force =mass * acceleration

Thrust - weight - air resistance =mass*acceleration

7464759 - 386369*9.81 - 90000 = 386369*a

3584479.11 =386369*a

a =3584479.11/386369

a=9.277 m/s upwards

ANSWER:  a=9.277 m/s upwards

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2)Given Total mass of vehicle = 1094 kg +415 kg =1509 kg

Force exerted by vehicle = 2132 N

a = 0.72m/s²

Find total Resisting Force

Here resisting force is the frictional force acting opposite to movement of vehicle

Net Force =mass*acceleartion

Force exerted by vehicle - Resisting Force =mass *acceleration

2132 N - Fr = 1509 kg *0.72m/s²

Only unknown is Fr

Fr = 2132 -1509*0.72

Fr = 1045.52 N

ANSWER: Resisting Force =1045.52 N

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