# Need help with physics magnitude and displacement

• squareone
In summary, the car displacement is 80 km west and 30 km south of west, and the overall displacement is 120 km.
squareone
1. A car is driven 80 km west and then 30 km 45 degrees south of west. What is the displacement of the car from the point of origin? (magnitude and displacement)

2. A delivery truck travels 18 blocks north, 10 blocks east, and then 20 blocks south. What is the trucks final displacement from its starting point? Assume the blocks are all equal length.

Also help with: Given the following two vectors, where Vector A is 6.3 meters and Vector B is 3.5 meters: Determine the magnitude of the following vector sums:

a. A+B
b. A-B
c. B-A

I don't know where to start. Every example i looked at didn't help me solve these and they seem to contradict each other. I'm just starting in physics and deeply confused. Please help...

Last edited by a moderator:
Have you studied vectors at all? Do you know how to add two vectors together? Subtract them?

Hint: Rather than throwing a bunch of the same kind of problems into one thread, it is preferred that you post a single problem in a single thread. That way, replies can be concise and to the point.

SteamKing said:
Have you studied vectors at all? Do you know how to add two vectors together? Subtract them?

Hint: Rather than throwing a bunch of the same kind of problems into one thread, it is preferred that you post a single problem in a single thread. That way, replies can be concise and to the point.
I'm taking this class over the summer and no i don't know anything about physics. Its been 5 years since i took Algebra

squareone said:
I'm taking this class over the summer and no i don't know anything about physics. Its been 5 years since i took Algebra
I'm not asking about physics. These problems are essentially math problems dealing with vectors. Do you know what a vector is?

squareone said:
I don't know where to start.

Try a diagram. Mark on it distances/length and angles. Complete any right angled triangles that spring to mind.

What branch of maths involves lengths, angles and triangles?

squareone said:
1. A car is driven 80 km west and then 30 km 45 degrees south of west. What is the displacement of the car from the point of origin? (magnitude and displacement)

Welcome to the PF.

Start with that question first. Draw a diagram of the 2 displacements, and use the Pythagorean Theorem to find the overall displacement vector...

## 1. What is magnitude in physics?

Magnitude in physics refers to the size or quantity of a physical quantity, such as force, velocity, or acceleration. It is usually represented by a number and a unit of measurement.

## 2. How do you calculate magnitude?

The method for calculating magnitude depends on the specific physical quantity. For example, the magnitude of a vector quantity (such as displacement or velocity) can be calculated using the Pythagorean theorem, while the magnitude of a force can be calculated using Newton's second law.

## 3. What is displacement in physics?

Displacement in physics refers to the change in position of an object in a specific direction. It is a vector quantity, which means it has both magnitude and direction. It is usually measured in units such as meters or centimeters.

## 4. How do you calculate displacement?

To calculate displacement, you need to know the initial position and the final position of an object in a specific direction. You can then subtract the initial position from the final position to find the displacement. This can be represented as d = xf - xi, where d is displacement, xf is the final position, and xi is the initial position.

## 5. What is the difference between magnitude and displacement?

The main difference between magnitude and displacement is that magnitude refers to the size or quantity of a physical quantity, while displacement refers to the change in position of an object. Magnitude is a scalar quantity, while displacement is a vector quantity. Additionally, magnitude does not have a specific direction, while displacement does.

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