AP Physics B Friction hates me!!

<p>An unknown mass is given a push and it slides down a 24° inclined plane, it travels 3 meters in 1.3 seconds before stopping on the incline. Assume the acceleration is constant.</p>

<p>(a) What is the coefficient of kinetic friction</p>

<p>I told my teacher another variable was needed to solve. She argues I don't. I argue back. I almost got a referral. </p>

<p>What do you guys think?</p>