You are Here: Home >< Physics

# Impact of constant force on speed watch

1. I was doing a past paper (multiple choice) and it had a question that asked about the impact of constant force on the speed of a car. Since it is constant force, it implies that there is net acceleration, which implies that the speed is constantly changing. Thus, shouldn't the speed-time graph for a net force acting on the car be a concave upwards graph like this? : (see image below)

To my surprise, the correct graph says that the speed is a straight line (y=mx+c) which in my opinion should be a velocity-time graph.

Attached Images

2. (Original post by Annie18451)
I was doing a past paper (multiple choice) and it had a question that asked about the impact of constant force on the speed of a car. Since it is constant force, it implies that there is net acceleration, which implies that the speed is constantly changing. Thus, shouldn't the speed-time graph for a net force acting on the car be a concave upwards graph like this? : (see image below)

To my surprise, the correct graph says that the speed is a straight line (y=mx+c) which in my opinion should be a velocity-time graph.

The force is constant, meaning the acceleration is also constant. Acceleration is the gradient on a velocity-time graph meaning the gradient is constant, and hence the graph is a straight line

Posted from TSR Mobile
3. (Original post by Kyx)
The force is constant, meaning the acceleration is also constant. Acceleration is the gradient on a velocity-time graph meaning the gradient is constant, and hence the graph is a straight line

Posted from TSR Mobile
Thanks! I just realised I made a silly mistake. I accidentally took it to be a displacement-time graph instead of a speed-time graph
4. (Original post by Annie18451)
Thanks! I just realised I made a silly mistake. I accidentally took it to be a displacement-time graph instead of a speed-time graph
Hehehe no problem

Posted from TSR Mobile

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 19, 2017
Today on TSR

### Edexcel C3 Maths Unofficial Markscheme

Find out how you've done here

### 1,478

students online now

Exam discussions

### Find your exam discussion here

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE