- #1
lecammm
- 9
- 0
As given by the attached question, we are given:
I think the relevant equations are:
ƩFy = 0;
ƩFx = ma;
F(friction) = N*μ
My attempt of the solution involved choosing my axis to be parallel to the slope (x axis) and y-axis perpendicular to the slope, then breaking the 51N force on the pulley up into it's components, i.e;
for x direction: 51cos(31)
for y direction: 51sin(31)
Then break up the boxes weight force into x & y components, i.e.
for x direction: (15*9.81)*cos(31)
for y direction: (15*9.81)*sin(31)
Next I summed the forces in the y direction to find the normal force N
i.e.
ƩFy = -(15*9.81*sin(31))+N+51(sin(31) = 0
Giving
N = 49.521
Next I found the force for friction giving:
F = 49.521*0.5
F = 24.7605
So then I tried to calculate the forces in the x direction with the positive direction being up the slope
ƩFx = 24.7605 + 51cos(31) + T - (15*9.81)*cos(31) + F = 15 * a
However I do not know where to find T, or if any of this working is correct, I'd really like some guidance on where to go from here, thanks.
- The force on the pulley, 51N
- The angle of the pulley, 31 degrees
- The mass of the box, 15 kg
- The angle of the incline, 31 degrees
- The kinetic friction coefficient, 0.5
I think the relevant equations are:
ƩFy = 0;
ƩFx = ma;
F(friction) = N*μ
My attempt of the solution involved choosing my axis to be parallel to the slope (x axis) and y-axis perpendicular to the slope, then breaking the 51N force on the pulley up into it's components, i.e;
for x direction: 51cos(31)
for y direction: 51sin(31)
Then break up the boxes weight force into x & y components, i.e.
for x direction: (15*9.81)*cos(31)
for y direction: (15*9.81)*sin(31)
Next I summed the forces in the y direction to find the normal force N
i.e.
ƩFy = -(15*9.81*sin(31))+N+51(sin(31) = 0
Giving
N = 49.521
Next I found the force for friction giving:
F = 49.521*0.5
F = 24.7605
So then I tried to calculate the forces in the x direction with the positive direction being up the slope
ƩFx = 24.7605 + 51cos(31) + T - (15*9.81)*cos(31) + F = 15 * a
However I do not know where to find T, or if any of this working is correct, I'd really like some guidance on where to go from here, thanks.