? (5) You and the Police Chietf ou are driving North through an intersection in

Question

? (5) You and the Police Chietf ou are driving North through an intersection in a ss mi/hr speed zone, when the local Chief of Police, who is driving his new Cadilc and a e. The two cars stick together and skid a distance 27.5 with locked wheels at an angle of 65,7e to the East of North. The mass of your car is 156.0 kg from the at an angle of 65.7° to the East of North. The mass of your car is 1566.0 kg while the Cadillac,has a mass 2068.0 kg speeding. The lockl judge is going to believe his Chief of some out-of-town hope for acquittal. Compute the speed of the Chief of Police immediately prior to the collision . The coefficent of sliding friction is 0.90. The Chief of Police is angry that you have damaged his new Cadillac and gives you a ticket for Police rather than some out-of-town student. You realize that the knowledge you learned in your physics course is your only Antwort eivreichen Versuche 0/8 Compute your speed immediately prior to the collision as evidence for or against the speeding ticket Antwort einreichen Versuche 0/8

Explanation / Answer

Here, the frictional force will stop the cars sliding.

Frictional force = µ . N = m . a

=> a = µ . m . g / m = 0.9 x 9.8 = 8.82 m/s^2

now use the expression -  

V^2 = 2 . a . d

=> V ( starting velocity after collision ) =?( 2 * 8.82 * 27.5 ) = 22.02 m/s

therefore -

Momentum along the slide = 22.02 * (1566.0 + 2068.0) = 22.02 * 3634 kgm/s

Momentum East = 22.02 * 3634 * cos 24.3? = 72931 kgm/s

Conservation of momentum says that this momentum must all have come from the vehicle traveling East. - the cop.

so -

72931 = m . v = 2068 . v

=> V ( police chief ) = 72931 / 2068 = 35.3 m/s

again,  

Momentum South = 22.02 * 3634 * sin 24.3? = 32930 kgm/s

Again, conservation of momentum says that this momentum must all have come from the vehicle traveling north - means my car.  

so -

32930 = m . v = 1566 . v

=> V ( my speed) = 32930 / 1566 = 21.0 m/s = 50 mile / hr.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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