Question

Lora (of mass 54 kg) is an expert skier. She

Answer 1

The mechanical energy at top =Mechanical energy at bottom

• Mass=m=54kg
• Height=h=51m
• Acceleration due to gravity=g=10m/s^2
• Velocity=v=2.6m/s

$\\ \tt\longmapsto M_{initial}=M_{Final}$

• Final energy at bottom=The kinetic energy

$\\ \tt\longmapsto KE=M_{initial}$

$\\ \tt\longmapsto KE=P.E_{(Top)}+K.E_{(Top)}$

$\\ \tt\longmapsto K.E=mgh+\dfrac{1}{2}mv^2$

$\\ \tt\longmapsto K.E=m\left(gh+\dfrac{v^2}{2}\right)$

$\\ \tt\longmapsto K.E=54\left((10)(51)+\dfrac{2.6^2}{2}\right)$

$\\ \tt\longmapsto K.E=54\left(510+\dfrac{6.76}{2}\right)$

$\\ \tt\longmapsto K .E=54(510+3.38)$

$\\ \tt\longmapsto K.E=54(513.38)$

$\\ \tt\longmapsto K.E=27722.52J$

$\\ \tt\longmapsto K.E=27.7KJ$