Force vector without acceleration

Click For Summary
SUMMARY

The discussion centers on calculating the force vector for a truck with a mass of 45 tons (90,000 pounds) pushing up a 30-degree incline. The force vector is derived using the equation F = ||F|| cosθ i + ||F|| sinθ j, leading to the expression F = 45 cos30 i + 45 sin30 j. However, the accuracy of this calculation hinges on the assumption that the truck is moving at a constant velocity, as clarified by a physics teacher. The problem's ambiguity regarding the truck's mass and the conditions of motion is highlighted as a significant issue.

PREREQUISITES
  • Understanding of vector components in physics
  • Knowledge of trigonometric functions (sine and cosine)
  • Familiarity with Newton's laws of motion
  • Basic concepts of force and weight in physics
NEXT STEPS
  • Study the implications of constant velocity on force calculations in physics
  • Learn about the differences between mass and weight, particularly in the context of the imperial system
  • Explore vector resolution techniques in two-dimensional motion
  • Review problem-solving strategies for physics word problems to improve clarity and precision
USEFUL FOR

Students studying physics, particularly those tackling mechanics and force vectors, as well as educators seeking to clarify concepts related to mass, weight, and motion on inclines.

miraiw
Messages
16
Reaction score
0
This is just to see if I am totally confused or making sense.

Homework Statement


A truck is pushing up a hill on a 30 degree incline. It has a mass of 45 tons. Find the force vector for the truck.

Homework Equations


[tex]\vec{F}[/tex] = ||F|| cos[tex]\theta[/tex] i + ||F|| sin[tex]\theta[/tex] j


The Attempt at a Solution


[tex]\vec{F}[/tex] = 45 cos30 i + 45 sin30 j
This is the answer that I assume was wanted, but I don't think that I can say what the force is given only the mass of the truck. After I asked my physics teacher (not the one who gave the quiz), he told me that this is the answer when moving at a constant velocity. If it was stated in the problem that the truck moved at a constant velocity is this correct?
 
Physics news on Phys.org
This is a poorly worded problem. Are you working in the USA system of measure? If so, the 45 ton 'mass' of the truck is really its weight...it weighs 90,000 pounds. With this assumption, and the assumptions that the truck is being pushed up the incline at constant velocity, and with a force parallel to the incline, and with no other forces acting on the truck besides its weight, and the x-axis is the horizontal axis, and the problem is asking for the pushing force vector, please show how you would arrive at that result for the pushing force vector, in units of pounds. The problem should be more specific in its wording, since there are too many assumptions you have to make.
 

Similar threads

Replies
12
Views
2K
Replies
1
Views
924
Replies
24
Views
3K
  • · Replies 16 ·
Replies
16
Views
2K
Replies
26
Views
4K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
3
Views
1K
  • · Replies 31 ·
2
Replies
31
Views
3K
Replies
1
Views
2K