Changing Velocity | Forces & Motion | Physics | FuseSchool

Подробнее о видео

CREDITS

Animation & Design:

Joshua Thomas

jtmotion101@gmail.com

Narration:

Dale Bennett

Script:

Bethan Parry, Keith Ross and Alistair Haynes


Have you ever been on a merry-go-round in a carnival? As you are swinging around, you are actually undergoing circular motion.

First of all, what’s the difference between velocity and speed? Speed is a measure of how far something travels, a distance, in a particular time

For example, A car travelling at 25 m/s or a person jogging at 4 m/s are both measures of speed.

Velocity is a speed in a particular direction. For example a van travelling north at 25 m/s and a raindrop moving down at 1 m/s.

For each of these statements decide whether they are a measure of speed or velocity.

When an object is moving in a circle at a constant speed, it has a certain velocity, v, which is at a tangent to the circle. At the same time, the mass is also accelerating towards the center of the circle. But you may be wondering, why is the object accelerating when the speed remains constant?

To understand this, we must review the factors that cause velocity to change. As you know, a change in velocity results in acceleration from this equation. Acceleration equals the change in velocity over time.

The two ways in which a velocity can change are:

1. A change in speed
2. A change in direction

So when you’re moving in a circle at a constant speed, your velocity is constantly changing, because the direction you are moving in is also constantly changing.

But you may be wondering… what actually causes the acceleration? As you know from Newton’s Second Law of Motion, the net force acting on an object is directly proportional to its acceleration.

In the case of circular motion, the net force that causes this acceleration is called the centripetal force, and it is always directed towards the center of the circle.

You can easily test this by attaching a ball to a string and swinging it round your head. The speed of the ball is constant but you need to keep pulling the string to make it go in a circle. What direction do you think the ball will follow if you suddenly let go of the string?

Is it in the red direction or the blue?

The ball will continue to travel in the same direction, so with the same velocity along the red direction. Try it yourselves and see!

So that’s how velocity can change whilst speed remains the same; by changing direction and not speed.


SUBSCRIBE to the FuseSchool YouTube channel for many more educational videos. Our teachers and animators come together to make fun & easy-to-understand videos in Chemistry, Biology, Physics, Maths & ICT.

VISIT us at www.fuseschool.org, where all of our videos are carefully organised into topics and specific orders, and to see what else we have on offer. Comment, like and share with other learners. You can both ask and answer questions, and teachers will get back to you.

These videos can be used in a flipped classroom model or as a revision aid.

Find all of our Chemistry videos here:


Find all of our Biology videos here:


Find all of our Maths videos here:


Twitter:

Access a deeper Learning Experience in the FuseSchool platform and app: www.fuseschool.org
Follow us:
Friend us:

This Open Educational Resource is free of charge, under a Creative Commons License: Attribution-NonCommercial CC BY-NC ( View License Deed: ). You are allowed to download the video for nonprofit, educational use. If you would like to modify the video, please contact us: info@fuseschool.org