Two cars collide at an intersection. Car A , with a mass of 1800kg , is going fr

Question

Two cars collide at an intersection. Car A, with a mass of 1800kg , is going from west to east, while car B, of mass 1300kg , is going from north to south at 12.0m/s . As a result of this collision, the two cars become enmeshed and move as one afterwards. In your role as an expert witness, you inspect the scene and determine that, after the collision, the enmeshed cars moved at an angle of 65.0? south of east from the point of impact.

A)How fast were the enmeshed cars moving just after the collision?

B)How fast was car A going just before the collision? ANSWER: 4.04m/s

Explanation / Answer

mA = 1800 kg        uAx = ?         vA = v

mB = 1300 kg         uBy = -12 m/s    vB = v

before collision initial momentum

Pix = mA*uA

Piy = mB*uB

after collision

Pfx = (mA+mB)*V*cos65

Pfy = -(mA+mB)*V*sin65

in any collision momentum is conserved

   Pfy = Piy

mB*uB = -(mA+mB)*V*sin65

V = -(mB*uB)/(mA+mB)*sin65

v = -(1300*12)/((1800+1300)*sin65) = -5.55 m/s

part (A)

speed of the cars after enmeshed = v = 5.55 m/s

part (B)

Pfx = Pix    

mA*uA = (mA+mB)*V*cos65

uA = (mA+mB)*v*cos65/mA

uA = ((1800+1300)*5.55*cos65)/1800

uA = 4.04 m/s <------answer

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

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