why the x component in the picture of the car is ( sin ) and in the second picture “ free body diagram “ the x component is ( cos ) .
is it always the x component (cos ), is not ?
- DixonLv 71 month ago
The angle is with respect to vertical in one diagram and horizontal in the other.
- oubaasLv 71 month ago
Pls have a look to the sketch shown below :
The gravitational force parallel to the incline that makes the body sliding down is GF = m*g*sin Θ and it is the force you have to overcome if you want to move the body up a frictionless incline .
If there is friction , then the friction force FF, parallel to the incline and having the same versus of GF, will be equal to m*g*cos Θ*μ , so the total force F to be applied will be equal to :
F = GF+FF = m*g*sin Θ + m*g*cos Θ*μ = m*g*(sin Θ + cos Θ*μ )
If the body is kept at rest by the only friction , then it must be :
m*g*sin Θ = m*g*cos Θ*μ
μ = sin Θ / cos Θ = tan Θ
- oldschoolLv 71 month ago
Remember cos30 = sin60 and sin30 = cos60