Question

While driving down the street, your friend’s car was hit by a truck from behind.  The mass...

While driving down the street, your friend’s car was hit by a truck from behind.  The mass of your friend’s car is 1500 kg while the truck is 1800kg.  Your friend was driving 25 mph or 11.2 m/s. Assume that collision causes both cars to stick together and they do not supply additional power to the wheels after the collision. After the collision, the two cars slide to a stop. The coefficient of kinetic friction is 0.65 for the car and truck with the road.

(15 pts) If the cars slide a total of 15 m after the collision, what was the speed of the connected cars at the start of the slide immediately following the collision?

(15pts) How fast was the truck moving before the collision? If you do not know the speed of the connected cars after the collision from part a), assume you know it and solve algebraically.

Homework Answers

Answer #1

let,


mass of the truck,m1=1500 kg


mass of the car, m2=1800 kg


speed of the car, u2=11.2 m/sec


coefficient of kinetic friction,uk=0.65


a)

after collision,


distance travelled, s=15m

and


force=uk*N


(m1+m2)*a==uk*(m1+m2)*g


==> a=-uk*g


a=-0.65*9.8


a=-6.37 m/sec^2


acceleration, a=-6.37 m/sec^2


and


v^2-u^2 =2*a*s


0-u^2=2*(-6.37)*15


===> u=13.834 m/sec

speed of the car and truck, just after collision, u=13.834 m/sec


b)

by using the conservation of momentum,


m1*u1+ m2*u2=(m1+m2)*u


1800*u1+1500*11.2=(1800+1500)*13.834

===> u1=16.029 m/sec


speed of the truck before the collision, u1=16.029 m/sec

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Passengers that are hit from behind in a car can suffer bodily injuries such as whiplash,...
Passengers that are hit from behind in a car can suffer bodily injuries such as whiplash, with accelerations of even small values such as 3.5g. Suppose a large pickup truck hits a small compact car from the back in a inelastic rear end collision that lasts .2 (s). The pickup truck’s mass is 3000kg while the compact car has a mass of 1000kg. The initial speeds of the pickup truck is 25 m/s and the compact car’s is 10 m/s....
Two cars, both of mass m, collide and stick together. Prior to the collision, one car...
Two cars, both of mass m, collide and stick together. Prior to the collision, one car had been traveling north at speed 3v, while the second was traveling at speed 2v at an angle ? south of east (as indicated in the figure). After the collision, the two-car system travels at speed vfinal at an angle ? east of north. (Figure 1) Find the speed vfinal of the joined cars after the collision. Express your answer in terms of v...
Car A hits car B (initially at rest and of equal mass) from behind while going...
Car A hits car B (initially at rest and of equal mass) from behind while going 15 m/s Immediately after the collision, car B moves forward at 10 m/s and car A is at rest. What fraction of the initial kinetic energy is lost in the collision?
You are an investigator at the scene of a car crash. A Volvo of has hit...
You are an investigator at the scene of a car crash. A Volvo of has hit an Alpha Romeo from the side and the two are inter-tangled (stuck together). You can see that the Volvo was traveling due east on a concrete road with a 50 mph speed limit and made a 30.0 m long skid mark before reaching the intersection where it hit the Alpha Romeo which was driving due North on a concrete road with a 25 mph...
Two cars collide at an intersection. Car A, with a mass of 2000 kg, is going...
Two cars collide at an intersection. Car A, with a mass of 2000 kg, is going from west to east, while car of mass 1500 kg, is going from north to south at 15 m/s. As a result, the two cars become enmeshed and move as one. As an expert witness, you inspect the scene and determine that, after the collision, the enmeshed cars moved at an angle of 52∘ south of east from the point of impact. How fast...
You are driving North through an intersection in a 55 mi/hr speed zone, when the local...
You are driving North through an intersection in a 55 mi/hr speed zone, when the local Chief of Police, who is driving his new Cadillac and approaching the intersection from the West, hits you broadside. The two cars stick together and skid a distance 38.9 m with locked wheels at an angle of 66.9° to the East of North. The mass of your car is 1425.0 kg while the Cadillac has a mass 2088.0 kg. The coefficent of sliding friction...
You are driving North through an intersection in a 55 mi/hr speed zone, when the local...
You are driving North through an intersection in a 55 mi/hr speed zone, when the local Chief of Police, who is driving his new Cadillac and approaching the intersection from the West, hits you broadside. The two cars stick together and skid a distance 38.3 m with locked wheels at an angle of 64.4° to the East of North. The mass of your car is 1590.0 kg while the Cadillac has a mass 1996.0 kg. The coefficient of sliding friction...
1.) Two bumper cars collide head-on. Car #1 has a mass (including the driver) of 120...
1.) Two bumper cars collide head-on. Car #1 has a mass (including the driver) of 120 kg, and is heading north at 5 m/s before the collision. Car #2 has a mass (including the driver) of 150 kg, and is heading south at 6 m/s before the collision. After the collision, Car #1 is heading south at 4 m/s. What is Car #2's velocity after the collision? 5.2 m/s north 1.2 m/s north 6.8 m/s south 6.8 m/s north 5.2...
Driving a fuel-efficient car was never really your way of living, because you believe that anthropogenic...
Driving a fuel-efficient car was never really your way of living, because you believe that anthropogenic climate change is a big hoax. While serving in the Army you learned to truly appreciate the advantages of driving a nice “Humvee” (from High Mobility Multipurpose Wheeled Vehicle = HMMWV). A (highway) gas mileage of 10mpg really does not scare you and you decide to invest in a fully equipped Hummer H1 with a curb weight of mH1 = 3685kg (Note: This is...
1. While enter a highway, a car accelrates from 15.m/s to 32.0m/s at a rate of...
1. While enter a highway, a car accelrates from 15.m/s to 32.0m/s at a rate of 2.90m/s^2. a. how far did the car travel while accelerating? b. how long did it take the car to accelerate from 15.0m/s to 32.0m/s^2 2.Using Newton's law of gravity, calculate the weight of a 90.0kg astronaut standing on the surface of a planet that has the same mass as the earth, but only half the radius of the Earth. 3. a 3,00kg pickup truck...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT