# The Effect of the Radius on Circular MotionWatch

Announcements
#1
Hi,

I’m quite confused because there are so many formulae which seem to contradict each other?

So if I want to increase centripetal acceleration, I would decrease the radius, but so doing, I would be decreasing the speed, which would decrease centripetal acceleration?

Furthermore, in this formula, , radius and acceleration are proportional to each other? But they were inversely proportional in the previous formula?

I’m confused.
0
4 years ago
#2
When thinking about direct and inverse proportionality with these equations, you need to remember what you're keeping constant in each case. In the first, you need your time period and hence angular velocity to be constant, but in the second you are keeping your linear velocity constant. So both are correct, but not at the same time.
For example, if you reduce radius, while keeping angular velocity constant, linear speed will increase and your first proportionality equation applies. But because linear speed isn't a constant, angular acceleration won't be inversely proportional to the radius, and the second equation doesn't apply
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• Manchester Metropolitan University
Wed, 19 Jun '19
• University of West London
Wed, 19 Jun '19
• University of Warwick
Fri, 21 Jun '19

### Poll

Join the discussion

#### How did your AQA A-level Biology Paper 2 go?

Loved the paper - Feeling positive (425)
18.69%
The paper was reasonable (1075)
47.27%
Not feeling great about that exam... (504)
22.16%
It was TERRIBLE (270)
11.87%

View All
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.