Most of us know that when the treads of our typical car tyres are worn out, we need to change as to provide grip, hence our car will not skid easily. But actually, the treads of our typical car serve a more important role during rainy days. They allow the water to be displaced (quickly letting the water to move into the treads) so that the tyres can still maintain contact with the road to provide the grip. Of course, if you still go too fast on a wet road, that layer of water may not be able to be displaced in time, hence grip on the road is greatly reduced and the car is likely to skid. Especially in the recent F1 race in Singapore, due to the wet weather, the cars had to changed to hard wet tyres. Many may be puzzled why F1 cars uses smooth slick tyres during dry weather, contrary to our common sense for our typical cars. The graphic below hopes to provide some basic explanation to the wet and dry tyre and the function of the tread on tyre. Hope it helps. The following video gives a good overview of how a tyre works. There is a lot of science behind them.

Take note how to phrase the action-reaction pair, and also the differences and similarities of a action-reaction pair.

1) Newton’s first law states that an object will remain at rest or in uniform motion (constant speed) in a straight line unless an external force acts on the body. In other words, when a body is at rest or moving at constant speed in a straight line (constant velocity) , straight away you should know it is Newton’s first law . Next you must know these 3 basics concepts about 1st law: – forces acting on the body are balanced – net force / resultant force acting on the body is zero – there is no acceleration. 2) Newton’s second law states that when a net force (resultant force) acts on a body , it will cause an acceleration on the body (accelerating or decelerating). Basically F = ma where F is the net or resultant force in N,m is the mass in kga is the acceleration in ms-2 In other words, when a body is moving faster or slower (or going round a bend), you should know its Newton’s second law . Next you must know these 3 basic concepts about 2nd law: – forces acting on the body are not balanced – there is a net force / resultant force acting on the body – there is an acceleration (accelerating of net force is in the direction of motion, or decelerating if the net force is opposite to the direction of motion)

Instead of the usual finding of potential difference across a component, in this question, you are required to find the p.d. across two points on the two separate branches. If you can relate the river system to the DC circuit, it will help in solving the last part. View the video tutorial

Do you understand why there is a potential difference between P and Q? What if you are to find the potential difference between P and Q? There is a shortcut to getting the answer for this MCQ, but watch the whole video to understand the concepts fully and find the value of the potential difference. Answer: Option D Video the explanation Another question with similar concept: 2012PPp2q07 https://www.sgphysicstuition.com/post/2012ppp2q07-find-the-p-d-across-a-and-c

Prefixes are used to denote very large or small physical quantities . It is important that you know all these prefixes well.

Light and sound are both waves. So both carry energy from one place to another. Light , which is part of the electromagnetic spectrum, is a transverse wave , It can travel through a vacuum at speed 3.0 x 108 m/s. As the light travels from an optically less dense medium (air) to an optically denser medium (liquid or glass) , the light undergoes refraction and bends towards the normal due to a decrease in speed . Light: Optically less dense medium to denser medium:  – speed decreases – wavelength shorter – frequency remains constant Sound is a longitudinal wave . It requires a medium to pass through and it cannot pass through a vacuum . Opposite to light, as the sound travels from a less dense medium (air) into a denser medium (water or solid) , the speed increases . Sound: Less dense medium to denser medium: – speed increases – wavelength longer – frequency remains constant Refers to the image below to understand how the waves behave in different mediums.

To do similar questions, it is important to know the 3 rays which have rules to follow in order to locate the image. Look through the video to learn the concepts and hopefully you can do similar questions in future.

In this post, we will be going to the basics of setting up the retort stand and pendulum experiment. Most probably, this will be the first experiment which you will perform in the lab. Let’s start with the setting up the retort stand, boss and the clamp. Next we will take a look at how you set the up the apparatus for the pendulum experiment.