Cathy is on a bike (m = 80 kg for both Cathy and the bike) at rest on the top of

Question

Cathy is on a bike (m = 80 kg for both Cathy and the bike) at rest on the top of a long ramp, she is a vertical distance of 20 meters above the ground, if we assume no friction, how fast is she going when she reaches the bottom of the ramp? 10 m/s 20 m/s 15 m/s 12 m/s 18 m/s If a roller coaster car starts from rest at a vertical height (h_1) of 30 m and goes around a loop, what is the speed of the car at the top of the loop that is h_2 = 10m off the ground? (assume no loss due to friction) 40 m/s 20 m/s 14 m/s 70 m/s 35 m/s

Explanation / Answer

19) from conservation of energy

mgh = 1/2mv^2

v = sqrt(2gh)

v = sqrt(2*9.8*20) = 19.79 m/s

20) 1/2mv^2 = mgh1-mgh2

v = sqrt(2g(h1-h2) = sqrt(2*9.8*20) = 19.79 m/s

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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