# Solving Horizontal Force Problems Involving Blocks

• jarny
In summary, the conversation discusses a physics problem involving two blocks and a constant horizontal force. The first scenario involves block A pushing against block B with a 23.0 N force and the second scenario has block B pushing against block A with an 11.0 N force. The combined mass of the blocks is 12.0 kg and the goal is to find the magnitudes of their acceleration and the applied force. The solution involves using the equation Fnet = ma and solving for the unknown variables. Eventually, the conversation reaches a solution where the applied force is found to be 17 N.
jarny

## Homework Statement

In Figure 5-50a, a constant horizontal force F->a is applied to block A, which pushes against block B with a 23.0 N force directed horizontally to the right. In Figure 5-48b, the same force is applied to block B; now block A pushes on block B with a 11.0 N force directed horizontally to the left. The blocks have a combined mass of 12.0 kg. What are the magnitudes of (a) their acceleration in Figure 5-50a and (b) force F->a?

## Homework Equations

Fnet=m*a

http://edugen.wiley.com/edugen/courses/crs1650/art/qb/qu/c05/fig05_50.gif

## The Attempt at a Solution

Ok so for block scenario one I have to find the Fnet to solve for m*a.
So I have Fnet= sum of forces=m*a

for case two

Fnet= sum of forces =m*a

So I have

12*a= Fapp+23-F_AB
12*a=Fapp-11+F_AB

I am stuck right here any tips?

Write down what you know.

Ma + Mb = 12

23N = Mb*a

11N = Ma*a

Since a is the same, then

Mb/Ma = 23/11

Mb = 12 - Ma = 23/11*Ma

Ma = 12*11/34 ...

Thank very much

Wait how would I found F->

Do I use: 23=F-> + X and 11=F-> -X ?

Then F->= 17 N?

What is your total mass and the acceleration of the system?

So the F->applied would be 12*a which I found?

jarny said:
So the F->applied would be 12*a which I found?

Isn't a the acceleration of both blocks?

And total mass is Ma + Mb.

So ...

Thanks

## 1. What is the definition of a horizontal force?

A horizontal force is a force that acts parallel to the surface of an object or in the direction of motion.

## 2. How do you calculate the net horizontal force on a block?

To calculate the net horizontal force on a block, you need to add up all the individual horizontal forces acting on the block. This can be done using vector addition or by using Newton's Second Law, F=ma, where F is the net force, m is the mass of the block, and a is the acceleration of the block.

## 3. What is the difference between static and kinetic friction?

Static friction is the force that prevents two surfaces from sliding against each other when they are not in motion. Kinetic friction, on the other hand, is the force that acts between two surfaces in motion.

## 4. How does the coefficient of friction affect the horizontal force on a block?

The coefficient of friction is a measure of the amount of friction between two surfaces. It affects the horizontal force on a block by determining the magnitude of the frictional force acting on the block. A higher coefficient of friction means a greater resistance to motion and therefore a larger horizontal force is needed to move the block.

## 5. What are some common strategies for solving horizontal force problems involving blocks?

One common strategy is to draw a free body diagram to identify all the forces acting on the block. Another is to break down the forces into horizontal and vertical components and use trigonometry to solve for the net force. Additionally, using equations such as Newton's Second Law and the equations for friction can help solve these types of problems.

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