# Help Can Someone Solve This Simple Physics Problem For Me?

Agahnim
Help! Can Someone Solve This Simple Physics Problem For Me??

hi i need help with a homework problem for physics: it goes like this:

A roller coaster car of mass 310 kg (including passengers) travels around a horizontal curve of radius 40 m. Its speed is 18 m/s. What is the magnitude and direction of the total force exerted on the car by the track?

_______N at _______° above the horizontal.

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The first answer I tried was calculating the normal force exerted by the track (which was simply mass * gravity, and 90 degrees above the horizontal). That was wrong. Then I tried giving the answer as the centripetal acceleration ((m * V^2)/ r), and the angle as 0 degrees above the horizontal. That was wrong too.

Homework Helper
Well, how about accounting for both gravity and cetripetal acceleration at the same time? Also, the force that the car exerts on the track (rather than the force the track exerts on the car) is what the problem is asking for.

Spectre5
Posted by the same person too

Agahnim
Ok, so if i understand it right:

Take the normal force (which is the same as gravity * mass) and say that it acts in the vertical direction. Then take the centripetal force as (v^2 * m)/r. Then add these two vectors together?