(adsbygoogle = window.adsbygoogle || []).push({}); finding friction coefficient without a mass??

A box slides down a 37.1o ramp with an acceleration of 1.29m/s2. (acceleration of gravity is 9.8m/s2) Determine the coefficient of kinetic friction between the box and ramp.

I just have no idea where to start with this since it doesn't give mass, so i can't draw that triangle to figure out weight, parallel force, or perpendicular force.

and another question..

1. A car is parked near a cliff overlooking the ocean on an incline that makes an angle of 25.7o with the horizontal. The negligent driver leaves the car on neutral, and the emergency brakes are defective.The car rolls from rest down the incline and has a velocity 20m/s when it reaches teh edge of the cliff. The cliff is 21.2 meters above the ocean. (acceleration of gravity is 9.8m/s2) How far is the car from the base of the cliff when the car hits the ocean?

I attempted to do this and somehow got to a quadratic equation adn then i used the quadratic formula and redid it about five times and still got it wrong. we haven't really finished learning this in class, so i'm not sure of how to do it.

it'd be great if someone felt like helping me...thanks a bunch

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# Homework Help: Two questions help please

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