PHYS 1104, Office Hour Problem Forces-1 Individual An express elevator is accele

Question

PHYS 1104, Office Hour Problem Forces-1 Individual An express elevator is accelerating upward with an acceleration of 4.00 m/s^2. A parcel was kicked and is now sliding to the right across the floor. The mass of the parcel is 5.00 kg and the coefficient of kinetic friction between the parcel and the floor is 0.500. a) What is the magnitude of the upward force exerted on the parcel by the elevator floor? b) Find the horizontal component of the parcel's acceleration. c) If the elevator suddenly switched from accelerating upward to acceleration downward what effect would this have on the horizontal component of the parcel's acceleration (no calculation is being asked for here, just a statement of what sort of change. if any, would occur)? Explain.

Explanation / Answer

a) a = 4 m/s2 in upwards direction.

on parcel :

in vertical :

N - mg = ma

N = 5 (9.8 + 4) = 69 N

b) in horizontal :

friction = u.N =0.5 x 69 =34.5 N

a =friction / m = 34.5 /5 = 6.9 m/s2

opposite direction of sliding direction.

c) now elevator is accelerating downwrads . then normal force due surface will decrease.

N = mg - ma

with less value N means less value of friction.

so if acting force will decrease then acc. willalso decrease accordingly.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

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