Crash Acceleration: Calculate SUV's Rate of Change in Velocity

  • Thread starter Thread starter simplekin93
  • Start date Start date
  • Tags Tags
    Acceleration Crash
AI Thread Summary
To calculate the acceleration of the SUV during the crash, the relevant kinematic equation is Vf^2 = Vi^2 + 2ad, where Vf is the final velocity (0 m/s), Vi is the initial velocity (12.5 m/s), and d is the distance (1.2 m). Rearranging the formula to solve for acceleration (a) allows for the calculation of the SUV's rate of change in velocity. By substituting the known values into the equation, the acceleration can be determined. It is crucial to consider the direction of the acceleration, which will be negative since the vehicle is decelerating. The final calculation will yield the SUV's acceleration during the crash.
simplekin93
Messages
5
Reaction score
0

Homework Statement


A person drives his SUV into a concrete wall. The car was initially moving East at 12.5m/s and the hood crumples a distance of 1.2m during the crash. What is the acceleration of the car during the crash? (don't forget directions when dealing with acceleration)

I don't even know where to begin.
 
Physics news on Phys.org
What constant acceleration formulae do you know?
 
almost all of them, i was given a big formula sheet that we are allowed to use in the test.
 
So this is what we have:

initial velocity (12.5ms-1)
final velocity (0.0ms-1)
distance (1.2m)

What we need:

acceleration

What formula do you know that uses only these variables?
 
Vf^2 = Vi^2 +2ad
 
Perfect! Now we just need to re-arrange that formula and solve for a!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...

Similar threads

Back
Top