# Magnitude of acceleration of block

• queenspublic
In summary, to find the magnitude of the acceleration of a block along a inclined plane, you need to find the net force acting on the block, then apply Newton's 2nd law.
queenspublic
How do I find the magnitude of the acceleration of a block along a inclined plane?

I am given the mass of the block = 4.15kg on a no-friction inclined plane of an angle 30 degrees.

What forces act on the block? Find the net force, then apply Newton's 2nd law.

What forces act on the block?

Would that be normal force which is the weight? (40.67? Am I right?)

Newton's 2nd law? F = ma

Can you explain that? How do I find F? m is given as 4.15. Am I right?

queenspublic said:
What forces act on the block?

Would that be normal force which is the weight? (40.67? Am I right?)
The normal force is one of the forces acting on the block, but it does not equal the weight.

The normal force acts perpendicular to the plane; the weight acts down. Draw a diagram and find components of the forces parallel and perpendicular to the plane.

My diagram has the normal force that keeps it up. The weight force pulling it down which opposite of normal force. And tension moving it forward. Am I right?

queenspublic said:
My diagram has the normal force that keeps it up. The weight force pulling it down which opposite of normal force.
No. If the weight were equal and opposite to the normal force, the block would just sit there.
And tension moving it forward.
Tension from what?

The weight force has components parallel and perpendicular to the incline. (What are those components?) The perpendicular component of the weight is equal and opposite to the normal force--so they cancel out. But that leaves the other component of the weight acting down the incline.

Last edited by a moderator:
Okay...so I used the m*g*sin30

m = 4.15
g = 9.8

and I still got the wrong answer.

then i divided by mass again and got wrong answer again.

We need more information to understand what has gone wrong. Show your calcs for normal force, friction force and force along the ramp. Finally, your F=ma calc to find the acceleration.

queenspublic said:
Okay...so I used the m*g*sin30
OK, that's the net force acting on the block.

m = 4.15
g = 9.8

and I still got the wrong answer.

then i divided by mass again and got wrong answer again.
If you want to find the acceleration, divide the net force by the mass. (F = ma → a = F/m.)

That's really all there is to it, assuming you've described the full problem exactly as it was given to you. If you are still not getting the right answer, please post the original problem word-for-word, including any diagrams given.

## What is the magnitude of acceleration of a block?

The magnitude of acceleration of a block refers to the rate of change of its velocity over time. It is a measure of how quickly the block's speed or direction is changing.

## How is the magnitude of acceleration of a block calculated?

The magnitude of acceleration of a block can be calculated using the formula a = (vf - vi)/t, where a is the acceleration, vf is the final velocity, vi is the initial velocity, and t is the time interval.

## What factors affect the magnitude of acceleration of a block?

The magnitude of acceleration of a block is affected by the net force acting on the block and its mass. A larger net force or a smaller mass will result in a larger magnitude of acceleration.

## How is the magnitude of acceleration of a block related to Newton's Second Law?

According to Newton's Second Law, the magnitude of acceleration of a block is directly proportional to the net force acting on the block and inversely proportional to its mass. This can be expressed as a = F/m, where a is the acceleration, F is the net force, and m is the mass.

## Can the magnitude of acceleration of a block be negative?

Yes, the magnitude of acceleration of a block can be negative if the block is slowing down or changing direction. However, the negative sign does not indicate a decrease in magnitude, but rather a change in direction.

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