ahmeeeeeeeeeed Posted April 3, 2012 Share Posted April 3, 2012 Hello at this problem the car is moving around the circle with constant speed , and it is asking for d^2R/dt^2 for the radar And d^2(theta)/dt^2 for the radar at the instance the speed of car is vertical downwards as shown the speed equals 120 km/hour And the radius of the circle is 450 so I said a® = (d^2R/dt^2) - R (omega^2) but the only acceleration is the central which equals (v^2/ Radius) and in the same direction so we can get d^2R/dt^2 . and when I try to get the (alpha)(d^2 theta / d t^2) a (theta) = R*(alpha) + 2 (omega)* (dR/dt) and a(theta) equals zero and here is my question , what is the value of dR/dt ??? I think it has to be zero , since the velocity is vertical and the unit vector R cap is horizontal so 1- Is Alpha zero ? 2- can dR/dT equal zero at that situation , while d^R/dt^2 has a value ? I think no problem but I wanted to make sure I'm right in this solution Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now