A luge and its rider, with a total mass of 86 kg, emerge from a downhill track o

Question

A luge and its rider, with a total mass of 86 kg, emerge from a downhill track onto a horizontal straight track with an initial speed of 38 m/s. Assume that they stop with a constant deceleration of 2.1 m/s2.
(a) What magnitude F is required for the decelerating force?
N

(b) What distance d do they travel while decelerating?
m

(c) What work W is done on them by the decelerating force?
kJ

(d) What is F for a deceleration of 4.2 m/s2?
N

(e) What is d for a deceleration of 4.2 m/s2?
m

(f) What is W for a deceleration of 4.2 m/s2?
kJ

Explanation / Answer

a) The only force acting on them in this case is the one causing the acceleration, so that it is as simple as F = ma. So, F = (86)(2.1 m/s/s)
b) Using kinematics,
vf2- vo2 = 2ax

You know they have in initial speed of 38 m/s, and a final velocity of 0 m/s. The acceleration is 2.1 m/s/s

Solve for x, which is how far they move during the acceleration.

c) Work is W = Fd, so simply multiply the values from parts a) and b)

d), e), f) Repeat the previous threesolutions, substituting 4.2 m/s/s for 2.1 m/s/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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