# science

A car has a crumple zone that is 0.80 m (80 cm) long. In this car, the distance from the dummy to the steering wheel is 0.50 m. The car has a mass of 1,600 kg and the dummy has a mass of 75 kg. At the time of the crash, the car has a speed of 18 m/s. Based on the work-energy theorem, what is the smallest possible force that the dummy could experience during the crash?

An SUV crashes into a wall. The mass of the vehicle is 2,150 kg and the crumple zone rigidity is 342 kN. Assuming the safety cell is perfectly rigid, what will be the acceleration of the SUV during a crash as the crumple zone is collapsing?

1. 👍
2. 👎
3. 👁
1. Normally I would use momentum but since you say use wok energy then'

initial KE of dummy = (1/2) m v^2 = .5 * 75 * 18^2
the dummy stops in .5 + .8 = 1.3 meters
force * distance = work = change in Ke
so
F * 1.3 = .5 * 75 * 18^2
==========================================
F = m a
342,000 = 2,150 a

1. 👍
2. 👎
👤
Damon
2. Damon would it be -0.159 or -159?

1. 👍
2. 👎

## Similar Questions

1. ### science

For a 1.00 m (100 cm) crumple zone, how much deformation do you think is needed in order to keep the passenger the safest?

2. ### science

An SUV crashes into a wall. The mass of the vehicle is 2,150 kg and the crumple zone rigidity is 342 kN. Assuming the safety cell is perfectly rigid, what will be the acceleration of the SUV during a crash as the crumple zone is

3. ### physics

several students are riding in bumper cars at an amusement park. the combined mass of a car A and its occupants is 250 kg. the combined mass of car B and its occupants is 200 kg. Car A is 15 m away from car B and moving to the

4. ### Physics

The front 1.20 m of a 1550 kg car is designed as a "crumple zone" that collapses to absorb the shock of a collision. (a) If a car traveling 26.0 m/s stops uniformly in 1.20 m, how long does the collision last? cannot_evaluate s

1. ### physics

A certain car can accelerate from rest to the speed v in time T seconds. (a) If the power output of the car remains constant, how long does it take for the car to accelerate from v to 3v, in terms of T? (b) How fast is the car

2. ### physics

A short train (an engine plus four cars) is accelerating at 1.10 . The mass of each car is 38000 , and each car has negligible frictional forces acting on it. In solving this problem, note the importance of selecting the correct

3. ### physics

a)Two cars are traveling along a straight line in the same direction, the lead car at 24.5m/s and the other car at 29.6m/s. At the moment the cars are 41.6m apart, the lead driver applies the brakes, causing her car to have an

4. ### physics

Cars A and B are racing each other along a straight path in following manner: Car A has head start and is a distance dA beyond starting line at t=0. The starting line is at x=o. Car A travels at constant speed vA. Car B starts at

1. ### physics

Please decide which of the following statements for car collisions are true or false. 1)Crumple zones on cars are parts of the front of the car that are designed to receive maximum deformation during a head-on collision. The

2. ### science- physics

A car is traveling at a steady 90 km/h in a 50 km/h zone. A police motorcycle takes off at the instant the car passes it, accelerating at a steady 7.3 m/s/s.How much time elapses before the motorcycle is moving as fast as the car?

3. ### physics

Car A is travelling at 22.0 m/s and car B at 29.0 m/s. Car A is 300 m behind Car B when the drive of car A accelerates his car with an acceleration of2.4 m/s2. How long does it take Car A to overtake Car B?

4. ### physics

A toy car runed off the edge of a table that is 1.225m high. If the car lands 0.400m from the base of the car to fall, a)how long does it take the car to fall 2(1.225)/-9.80=-0.25=0.5s b)what is the horizontal velocity of the car?