A spaceman of mass 80 kg is sitting in a spacecraft near the surface of the Earth. The spacecraft is accelerating upward at five times the acceleration due to gravity. What is the force of the spaceman on the spacecraft?

Answer: 4800 N

A spaceman of mass 80 kg is sitting in a spacecraft near the surface of the Earth. The spacecraft is accelerating upward at five times the acceleration due to gravity. What is the force of the spaceman on the spacecraft?

Answer: 4800 N

Tutors, please sign in to answer this question.

New Wilmington, PA

By Newton's 3rd law, the force of the spaceman on the spacecraft is equal and opposite to the force of the spacecraft on the spaceman, which is the normal force, F_{n}. From Newton's 2nd law,

F = F_{n} - mg = ma =m (5g)

F_{n} = 6mg = 6*80kg*9.8m/s² ≈ 4800 N.

Scottsdale, AZ

Apply Newton's second law in vertical direction:

F - mg = ma

But a = 5g. So,

F = 6mg = 6*80*10 = 4800 N, where g = 10 m/sec^2

Malik K.

MIT Grad, Math/Physics Tutor, Summer Math/Engineering Camp Instructor

New York, NY

5.0
(17 ratings)

John K.

Ardent Mathematics, Science, History, SAT and German Polymath

College Point, NY

5.0
(50 ratings)

Nikunj P.

Math and Science Specialist, Over 14 Years of Educational Experience

Scarsdale, NY

4.9
(88 ratings)

Find a tutor fast. Get the app.

Are you a tutor? Get the app for tutors

© 2005 - 2016 WyzAnt, Inc. - All Rights Reserved

## Comments

^{2}. Isn't that slow for a spacecraft?