Need help on the Exercise Part. PRACTICE IT Use the worked example above to help

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Need help on the Exercise Part. PRACTICE IT Use the worked example above to help you solve this problem. An pickup truck with mass 1.70 x 103 kg is traveling eastbound at +14.8 m/s, while a compact car with mass 8.57 x 102 kg is traveling westbound at -14.8 m/s. (See figure.) The vehicles collide head-on, becoming entangled. (a) Find the speed of the entangled vehicles after the collision. 4.88 m/s (b) Find the change in the velocity of each vehicle. Aycar 19.68 m/s (c) Find the change in the kinetic energy of the system consisting of both vehicles. 249ES 363 EXERCISE HINTS: GETTING STARTED I 'M STUCKI Use the values from PRACTICE IT to help you work this exercise. Suppose the same two vehicles are both traveling eastward, the compact car leading the pickup truck. The driver of the compact car slams on the brakes suddenly, slowing the vehicle to 5.21 m/s. If the pickup truck traveling at 18.1 m/s crashes into the compact car, find the following (a) the speed of the system right after the collision, assuming the two vehicles become entangled m/s (b) the change in velocity for both vehicles A'truck Avcar m/s m/s (c) the change in kinetic energy of the system, from the instant before impact (when the compact car is traveling at 5.21 m/s) to the instant right after the collision Noed Help? Read 8 scrollbars-no,resizable-yes, menuba openWindowt/v4cgi/quest ions/hint.tpl?id-220&wide-2;&title; Active Example, 'hint2, 'height 290,width 445

Explanation / Answer

Now before the collision the momentum of the system will be,

(1.7*103*18.1)+(8.57*102*5.2)

=35226.4

And after the collision let the speed of the system be V,

New mass will be

1.7*103+8.57*102

2557 Kg

So

New momentum will be= 2557V

And it will be equal to momentum before collision so

2557V=35226.4

V=13.776

b)

change in velocity of truck=13.776-18.1=-4.3235

change in velocity of compact car= 13.776-5.21=8.566

c)

Change in kinetic energy will be

kinetic energy before collision,

1/2(1.7*103*18.12)+1/2(8.57*102*5.212)

=290099.7469J

And kinetic energy after collision will be

1/2(2557*13.7762)

=242631.398J

So change will be

290099.7469-242631.398

=47468.348J

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