2 boxes on flat ground and an incline

In summary, the conversation discusses the calculation of the rate of acceleration and tension in a system consisting of a 10 kg box on a level surface attached to a 7.0 kg box on a 30 degree incline. The first part considers the scenario with no friction, while the second part introduces a coefficient of friction of 0.10 for both boxes. The discussion involves drawing a free body diagram and identifying the various forces acting on each body, as well as finding the net force and using F=ma to solve for the acceleration. A question is raised about the relationship between F_net, F_gravity, tension, and friction, leading to an expression with two variables.
  • #1
Quevvy
5
0
1. A 10 kg box on a level surface is attached by a weightless, unstretchable rope to a 7.0 kg box which rest on a 30 degree incline. Find the rate of acceleration and the tension in the rope if... a) there is no friction ... b) coefficient of friction is 0.10 for both boxes



2. F_net = m*a



3. Honestly, I'm not sure where to start
 
Physics news on Phys.org
  • #2
Start with the box on the slope. Draw the force of gravity straight down and calculate its size in N. Draw a pair of vectors that begin and end in the same place as that first one, an arrow along the slope and another straight into the slope. Use trigonometry to figure out the size of each of these vectors. The force into the slope is canceled out (the slope pushes back equally), so it is the component along the slope that causes the two masses to accelerate. Use F = ma.
 
  • #3
Do you know how to draw free body diagram? Identify the various forces acting on each body.
Find the net force acting in the downward direction. From that find the acceleration.

Edit: Hi Delphi51, we are racing.
 
  • #4
Delphi51 said:
Start with the box on the slope. Draw the force of gravity straight down and calculate its size in N. Draw a pair of vectors that begin and end in the same place as that first one, an arrow along the slope and another straight into the slope. Use trigonometry to figure out the size of each of these vectors. The force into the slope is canceled out (the slope pushes back equally), so it is the component along the slope that causes the two masses to accelerate. Use F = ma.

rl.bhat said:
Do you know how to draw free body diagram? Identify the various forces acting on each body.
Find the net force acting in the downward direction. From that find the acceleration.

So is the F_net = F_gravity parallel - F_tension - F_friction? because that is what I got after drawing a free body diagram...

EDIT: and now I'm trying to solve and I'm getting an expression with two variables - tension and acceleration
 

FAQ: 2 boxes on flat ground and an incline

How does the angle of the incline affect the movement of the boxes?

The angle of the incline determines the force of gravity acting on the boxes. As the angle increases, the force of gravity pulling the boxes down the incline also increases, making them move faster.

What factors affect the friction between the boxes and the incline?

The factors that affect friction include the weight of the boxes, the material of the boxes and the incline, and the smoothness or roughness of the surface. The greater the weight and the roughness of the surface, the higher the friction will be.

Is the force of gravity different between the two boxes?

No, the force of gravity is the same for both boxes as long as they have the same mass. However, the angle of the incline may affect the force of gravity acting on each box differently.

How does the position of the boxes on the incline affect their movement?

The position of the boxes on the incline can affect their movement in several ways. If the boxes are placed closer to the bottom of the incline, they will have a shorter distance to travel and will move slower. If the boxes are placed higher up on the incline, they will have a longer distance to travel and will move faster.

Can the boxes move without any external force acting on them?

No, according to Newton's First Law of Motion, an object at rest will remain at rest and an object in motion will remain in motion unless acted upon by an external force. Therefore, the boxes will need an external force, such as gravity or a push, to start or continue moving on the incline.

Back
Top