F=ma problem, I feel retarded because I can't get it

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AI Thread Summary
The discussion centers on a physics problem involving force and acceleration using the formula F=ma. The user correctly calculated the maximum force exerted by an empty truck as 2100 N but struggles with finding the maximum acceleration when the truck carries an additional 500 kg load. The confusion arises from not considering the total mass of the truck when calculating acceleration; the total mass is 2000 kg (1500 kg truck + 500 kg load). Using the correct total mass, the acceleration should be calculated as 2100 N divided by 2000 kg, resulting in 1.05 m/s². The key takeaway is to always account for the total mass when applying the formula F=ma.
phx1
Seriously I feel so stupid because I can't get the answer to the second part of the problem, what am I doing wrong?

Homework Statement



2 parts to the problem:

An empty truck whose mass is 1500 kg has a maximum acceleration of 1.4 m/s^2 . What is the maximum force that accelerates the truck? ______N

What is the maximum acceleration when it is carrying a 500 kg load? (hint: same force, but new total mass) ______m/s^2

Homework Equations



F=ma

The Attempt at a Solution



This is for a web based quiz and I got the first part right, it's obviously 2100 N, so then I figured: ok, so to find the acceleration using the same force just solve for a, therefore it should be 2100 N/500 kg, which gives me an answer of 4.2 m/s^2. It's telling me the 2100 N is correct, but not the 4.2 m/s^2 ... what am I doing wrong or not taking into consideration? It's so easy I'm just missing it...
 
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Force = TOTALmass * acceleration

What is the TOTALmass
 
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