Posted by Nat on .
a bell is hanging by a string from your review mirror in the car.while you are accelerating from a stoplight to 28m/s in 6s, what angle does the string make with the vertical?
(the bell only feel the car's acceleration through the tension in the string.)

physics 
drwls,
Draw a free body diagram. The horizontal component of the string tension force provides the acceleration (28/6 = 4.667 m/s^2) , and the vertical component supports the weight.
The mass will cancel out when you get the tangent of the angle of the string, so you do not need to know it. 
physics 
Nat,
how do i find the vertical component?
weight=mg but i don't know what m is. 
physics 
drwls,
As I already stated, it is the ratio of ma to mg that gives you the tangent of the angle. The mass cancels out. So does the tension, T
T sin theta = ma
T cos theta = mg
(sin theta)/(cos theta) = tan theta = a/g