Bobsled Friction Problem: Finding Velocity with Coefficient of Kinetic Friction

[RaiderXero]

Homework Statement

A bobsled (600kg) enters a straightaway at 19.2 m/s and travels 200m. If the coefficient of kinetic friction is .15, what is the velocity at the end of the straightaway?

Homework Equations

My friend asked me for help on this problem, but its been a while since I've taken physics. Can anyone point me to an equation that might help get us started?

The Attempt at a Solution

I know the force of kinetic friction will be 5880*.15= 882 and that vf^2 - vi^2 = 2a(x) is probably the equation to use, I am just lost on how to turn that kinetic friction into acceleration so I can use it.

 

[Doc Al]

Use Newton's 2nd law.

 

[Moetasim]

To solve this problem, we need to use the equation F=μmg, where F is the force of kinetic friction, μ is the coefficient of kinetic friction, m is the mass of the bobsled, and g is the acceleration due to gravity (9.8 m/s^2). We can rearrange this equation to solve for the acceleration (a=F/m).

Next, we can use the equation vf^2 - vi^2 = 2a(x), where vf is the final velocity, vi is the initial velocity (19.2 m/s), a is the acceleration we just calculated, and x is the distance traveled (200m). Rearranging this equation, we get vf = √(vi^2 + 2ax).

Plugging in the values, we get vf = √(19.2^2 + 2*(882/600)*200) = √(368.64 + 588) = √956.64 = 30.93 m/s. Therefore, the velocity at the end of the straightaway is approximately 30.93 m/s.

It's important to note that this is just an approximation, as there may be other factors such as air resistance that can affect the final velocity. Also, it's always a good idea to double check your units to ensure they are consistent throughout the calculation. I hope this helps you and your friend with your homework problem.