Simple acceleration, force, and mass question

  • #1

Homework Statement



A 30 tonne jumbo jet accelerates down the runway at 4 m/s².What must be the thrust on
each of its four engines?


Homework Equations



Acceleration = force/mass

the formula gives acceleration in m/s², provided that the force is in N and the mass is in kg


The Attempt at a Solution



This is what I attempted (Not sure if it's correct)

Firstly, we need to convert the tonne into kg. Therefore, 30 tonne = 30000kg

Step 1: Acceleration = force/mass
Step 2 (embedding the digits): 4 = f/30000
Step 3 (multiplying both sides by 30000) 4 x 30000 = f/30000 (30000)
Step 4 (Simplifying) 120000 = F

I found that my answer is 120000 Newtons (N) is the total thrust but because there is 4 engines, we must divide the force by 4, which will amount to 30000 newtons on each engine.

^that is my reasoning for this question which I suspect is probably flawed in one way or another for a couple of reasons. I'd like your help in knowing if I did something incorrect and if so, I'd like your help in correcting it.
 

Answers and Replies

  • #2
Dick
Science Advisor
Homework Helper
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Homework Statement



A 30 tonne jumbo jet accelerates down the runway at 4 m/s².What must be the thrust on
each of its four engines?


Homework Equations



Acceleration = force/mass

the formula gives acceleration in m/s², provided that the force is in N and the mass is in kg


The Attempt at a Solution



This is what I attempted (Not sure if it's correct)

Firstly, we need to convert the tonne into kg. Therefore, 30 tonne = 30000kg

Step 1: Acceleration = force/mass
Step 2 (embedding the digits): 4 = f/30000
Step 3 (multiplying both sides by 30000) 4 x 30000 = f/30000 (30000)
Step 4 (Simplifying) 120000 = F

I found that my answer is 120000 Newtons (N) is the total thrust but because there is 4 engines, we must divide the force by 4, which will amount to 30000 newtons on each engine.

^that is my reasoning for this question which I suspect is probably flawed in one way or another for a couple of reasons. I'd like your help in knowing if I did something incorrect and if so, I'd like your help in correcting it.

I think it's perfectly correct.
 

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