Calculating the Net Force Acting on a 2.75 kg Object

AI Thread Summary
To calculate the net force on a 2.75 kg object moving in a plane, the second derivatives of the position equations for x and y were taken to find acceleration. Substituting t = 2.35 s into these derivatives yields the accelerations, which are then multiplied by the mass to find the force components Fx and Fy. The magnitude of the net force is determined using the formula √(Fx² + Fy²). The initial calculation of 104.5 N was marked incorrect, and another participant suggested the correct answer is 198 N, indicating a possible arithmetic error in the original calculation. Accurate calculations are crucial for correct results in physics problems.
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Homework Statement



A 2.75 kg object is moving in a plane, with its x and y coordinates given by x = 7t^2 - 4 and y = 5t^3 + 1, where x and y are in meters and t is in seconds. Find the magnitude of the net force acting on this object at t = 2.35 s.

Homework Equations



F=ma

The Attempt at a Solution



I took the 2nd derivative of each posn eqn and then substituted 2.35s for t to get accel; multiplied each accel by 2.75 kg to get Fx and Fy; then took the sqrt of (Fx^2 + Fy^2) to get magnitude.

I am not sure how to proceed. Thanks for any help!
 
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Write the answer down and turn the question in, you already got it.
 
Thanks. I calculated the answer to be 104.5 N but it was marked as incorrect by the web program I use to turn in assignments. So something isn't right.
 
I got 198 N, you must've made an arithmetic error.
 

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