The force F = (3.2, -7.1) N acts on a mass of 1.15 kg. At time t = 0 s, the mass has a velocity v0 = (-0.46, 0.36) m/s.
What is the angle (in degrees) of the initial velocity, measured counter-clockwise from the +x-axis?
I got 38.04 degrees but isn't the right answer
Since they are asking about initial conditions only, the force makes no difference
Vo,x = -0.46 m/s
Vo,y = 0.36 m/s
The Vo vector is aimed in the second quadrant, at an angle of arctan36/46 = 38 degrees to the -x axis. That would be an angle of 142 degrees from the +x axis, measured counterclockwise.
To find the angle of the initial velocity, we can use trigonometric functions. The angle can be calculated using the components of the velocity vector: v0 = (-0.46, 0.36) m/s.
The angle can be determined by using the inverse tangent function, arctan(y/x), where x and y are the components of the vector. In this case, x = -0.46 and y = 0.36.
The arctan(0.36/-0.46) gives us -39.68 degrees.
However, we want the angle measured counter-clockwise from the +x-axis. Since the result obtained is negative, we need to add 360 degrees to it to get the angle in the desired range.
So, -39.68 + 360 = 320.32 degrees.
Thus, the angle measured counter-clockwise from the +x-axis is 320.32 degrees.