# Recent content by James22

1. ### Design of an automotive bumper

Thank you SirAskAlot, I completed the calculations for the spring bumper using your assistance. Now I have to design a bumper using some type of foam. My professor provided me with a few graphs of the characteristics of foam (PSI vs deflection). I have decided to use a 65.5" wide by 6" tall...
2. ### Design of an automotive bumper

1. Homework Statement I have attached the assignment below. The weight of the car will be 3702lbs 2. Homework Equations 3. The Attempt at a Solution I am not sure if I am on the right track, but so far I have calculated the kinetic energy as; E=1/2 mv^2 0.5 x...
3. ### Design of an automobile bumper

I worked on this project some more and calculated the kinetic energy as; E=1/2 mv^2 0.5 x (3702/32.2) x 7.33ft/s^2 = 3091.38 ft-lb I have chosen to use a 6" crumple zone and 4 springs to absorb the impact. This is where I run into trouble trying to get my head around the concept...
4. ### Design of an automobile bumper

1. Homework Statement I have posted the assignment hand out. The weight of the car will be 3702lbs. 2. Homework Equations 3. The Attempt at a Solution Right now I am overwhelmed with this project, I am not really sure where to start. Here is my thoughts on where to start...
5. ### Trouble with calculating acceleration from velocitity using calculus

Thank you Cepheid, I understand now.
6. ### Trouble with calculating acceleration from velocitity using calculus

I don't understand what is happening after the a=v dv/ds statement. If someone could explain the steps using calculus to end up with a=0.04s + 2 I would really appreciate it. I am trying to figure it out by reading over my old calculus notes, but I can't make a connection between the two...
7. ### Projectile Problem

Thanks for the reply. I have the horizontal speed as 80cos55 = 45.89ft/s I am unsure of how to calculate the height at which the ball hits the ground. Could someone shed some light as to how I would go about this. Thanks in advance.
8. ### Projectile Problem

1. Homework Statement There is the question I am having trouble with. All the data is given in the image. I am to find "d". The slope being on an angle is what is throwing me off. It would be simple enough if the ground was perfectly horizontal, but I am not sure how to handle the 10...