Problem 3: a skier of mass m starts at rest at the top of a ski jump ramp (Figur

Question

Problem 3: a skier of mass m starts at rest at the top of a ski jump ramp (Figure)(a) Use an energy conservation equation to find an expression for the skier's speed as she flies off the ramp. There is negligible friction between the skis and the ramp, and you can ignore air resistance. (b) After the skier reaches the ground at point Pin Figure, she begins braking and It at point Q. Find an e that acts on her between points P and Q. Ans: (a)2gH -D (b) Friction force -mg(+D) Skier, mass m Speed, v,-? Friction force fk

Explanation / Answer

a) Potential energy of skier at height H=mgH

Kinetic energy at that point = 0(because speed is zero)

Total energy of skier at that point= mgH+0=mgH

Potential energy of skier when just flying off the ramp = mgD

Kinetic energy of sklier = 0.5*m*v2

Total energy at this point = mgD+0.5*m*v2

From conservation of energy, mgH = mgD+0.5*m*v2

v = sqrt[(2g(H-D)]

b) Potential energy of skier when at top most point (considering point Q as datum)= mg(H+h)

Let friction forvce be F

Energy lost to friction in travelling from P to Q = FL

Energy of skier at Q=0

Therefore, total potential energy lost to friction = mg(H+h)

FL = mg(H+h)

F = mg(H+h)/L

The answer given in question is incorrect

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.