Question

A 1.10 kg box slides down a rough incline plane from a height h of 1.75 m. The box had a speed of 2.99 m/s at the top and a speed of 2.56 m/s at the bottom. Calculate the mechanical energy lost due to friction (as heat, etc.).

Answer 1

Answer:

20.18 J

Explanation:

We are given that

Mass of bx=m=1.1 kg

Height=h=1.75 m

Initial speed of box=u=2.99 m/s

Final speed,v=2.56 m/s

We have to find the mechanical energy lost due to friction.

Energy at top=$K.E+P.E=\frac{1}{2}mu^2+mgh=\frac{1}{2}(1.1)(2.99)^2+1.1\times 9.8\times 1.75=23.78$ J

Where $g=9.8 m/s^2$

At bottom,h'=0

Energy at bottom=$\frac{1}{2}mv^2+mgh'=\frac{1}{2}(1.1)(2.56)^2+0=3.6 J$

Energy lost=Energy(Top)-Energy(bottom)=23.78-3.6=20.18 J