Problem 3 (10 points) Two vehicles are approaching an intersection. One is a 120

Question

Problem 3 (10 points) Two vehicles are approaching an intersection. One is a 1200-kg car traveling at 48mi/h from west to east (the +x-direction), and the other is a 1100-kg car going from south to north (the ty-direction at 35.7 mi/h). (a) Find the x- and y-components of the net momentum of this system. Px (kg·m/s) (kg·m/s) (b) What are the magnitude and direction of the net momentum? Magnitude Direction (kg m/s) (angle with respect to east) (c) The cars collide in the intersection, lock bumpers and move together in one direction. Calculate the speed and the direction of the cars after the collision. (d) What kind of collision was it? Explain.

Explanation / Answer

Given,

m1 = 1200 kg ; u1 = 48 mph = 21.46 m/s

m2 = 1100 kg ; u2 = 35.7 mph = 15.96 m/s

a)Px = m1 v1

Px = 1200 x 21.46 = 25752 kg-m/s

Py = m2 v2

Py = 1100 x 15.96 = 17556 kg-m/s

Hence, Px = 25752 kg-m/s and Py = 17556 kg-m/s

b)magnitude of the net momentum will be:

P = sqrt (Px^2 + Py^2)

P = sqrt (25752^2 + 17556^2) = 31167 kg-m/s

Theta = tan^-1(17556/25752) = 34.28 deg

Hence, P = 31167 kg-m/s and theta = 34.28 deg

c)Intial momentum of the system is:

Pi = m1 u1 + m2 u2

Pf = (m1 + m2) Vf

vf = (m1 u1 + m2 u2)/(m1 + m2)

vf = (1200 x 21.46 + 1100 x 15.96)/(1200+1100) = 18.83 m/s

Hence, vf = 18.83 m/s

d)The collision is inelastic since only momentum is conserved but not the energy of the system.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

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