# Recent content by Turtlie

1. ### Acceleration from min/max derivatives

Ah looks like I was right then, and thank you for the hint ;) I've got another question. A flywheel car is capable of giving a car a constant acceleration of 0.5m/s2, but only for as long as it is wound up for (if it is wound up for 5 seconds it will accelerate at 0.5m/s2. Once the flywheel...
2. ### Acceleration from min/max derivatives

Homework Statement x(t) = -0.01t^3 + t^2 - 20t + 4 Homework Equations Min is when t = 12.3 Max is when t = 54.4 The Attempt at a Solution I got -0.03t^2 + 2t - 20 as the derivative. I substituted in t = 12.3 and 54.4 and got 0.02 and 0.19 which don't seem right at all. Because...
3. ### Rocket Height

Homework Statement A rocket, initially at rest on the ground, accelerates straight upward from rest with constant acceleration 53.9 m/s^2. The acceleration period lasts for time 7.00 s until the fuel is exhausted. After that, the rocket is in free fall. Find the maximum height ymax reached by...
4. ### Adding Scalar Multiples of Vectors Graphically

Wait so which arrow would be the answer? The one that I labeled as 3? Edit: Well 3 isn't the answer. I tried that one so now I have like 1 try left.
5. ### Adding Scalar Multiples of Vectors Graphically

Is that right? Not completely sure about four though :confused:
6. ### Adding Scalar Multiples of Vectors Graphically

Homework Statement Draw the vector C = 1.5A -3B (Mastering Physics problem) A is 4.5 and B is 1.0 The Attempt at a Solution I've tried it 4 times and still can't do it. I've looked at some sites but I guess I just don't understand it. I've heard of the head to tail method, or something...