# Force_21

## Centripetal force sources – sources of centripetal forces

In this post, you will find a List of Common circular motions and the sources of centripetal force (in tabular format) for each of these motions. Any force can be a centripetal force. Centripetal force is an umbrella term given to any force that is acting perpendicular to the motion of an object and thus […]

## Centripetal And Centrifugal Force

In this post, we will define centripetal force and centrifugal force, and find out how these two differ from each other. We will also go through some examples of these forces. In this discussion, we will also understand what centripetal acceleration is. Defining Centripetal Force Centripetal Force (Fc) is the force that sustains the circular […]

## pulley systems: block and tackle

A block and tackle is a compact system of pulleys designed to raise heavy loads. The block and tackle system has one cable or rope wound around two separate sets of pulleys. The pulleys of each set rotate freely on the same axle. The upper set is fixed to a support, and the lower set […]

## coefficient of static friction (μs) = tan θ

In this post, we will see how the coefficient of static friction (μs) = tan θ, where θ is the angle of inclination where static friction becomes the highest. In other words, θ is the angle of inclination when friction equals the value of limiting friction. (The maximum possible frictional force before the object starts […]

## Coefficient of Restitution – definition, formula, numerical

In this post, we will cover the definition and formula of the coefficient of restitution. We will also see how types of collision can be determined from the value of the coefficient of restitution. We will also solve a numerical problem using the formula of the coefficient of restitution. What is the Coefficient of Restitution? […]

## Three things are worth noting about frictional forces

Three things are worth noting about frictional forces: these fundamental points will help you to understand friction as a force, answer questions from the friction chapter and solve numerical problems based on friction. Here are the points: The smaller µ is, the more slippery the surface. For instance, ice will have much lower coefficients of […]

## Types of pulleys and how they differ in their operation

In this post, we will discuss three types of pulleys, and how they operate, and how they differ in their operation and utilities. The types we will discuss are (1) Fixed Pulleys, (2) Movable Pulleys, (3) the Block and Tackle.

## Examples and Practical use of Inelastic collisions

In this post, we will study a few examples of Inelastic collisions. Also, we will study an important practical use of Inelastic collisions.

## Equations valid for elastic collisions

In this post, we will briefly mention the equations valid for elastic collisions. We can use these equations to solve numerical problems related to elastic collisions. The Equation for the conservation of momentum (for elastic collision) Now, to solve problems involving one-dimensional elastic collisions between two objects, we can use the equation for the conservation […]

## Explosion and Conservation of Momentum

An explosion can be thought of as a single object separating into two or more fragments. In this post, we will see if the law of conservation of momentum is maintained during an explosion. We will solve related numerical problems as well. Some familiar examples of explosions are: a bomb blowing into fragments a bullet […]

## Toppling, stability & the position of the centre of mass of a body

The position of the center of mass of a body affects whether or not it topples over easily. This is important in the design of such things as tall vehicles (which tend to overturn when rounding a corner), racing cars, reading lamps, and even drinking glasses. A body topples when the vertical line through its […]

## Locating the Centre of mass using a plumb line

In this post, we will see how to find the centre of mass using a plumb line. Suppose we have to find the centre of mass of an irregularly shaped lamina (a thin sheet) of cardboard. Steps to follow to locate the centre of mass of an irregularly shaped lamina (a thin sheet) of cardboard […]

## AQA GCSE Physics – Equations & Formulae from Forces chapter

The image below shows a list of equations and formulae from the chapter “Forces” of the GCSE Physics syllabus. This is also helpful for all other equivalent boards like CBSE, ISC, ICSE. Equations to learn from the ‘Forces’ chapter Get the equations of weight, work done, spring force, the moment of force, pressure, distance traveled, […]

## Atwood machine when pulley has a non-zero mass

In this post, we will analyze one Atwood machine when its pulley has a non-zero mass. As a result this pulley has a nonzero moment of inertia. when pulley has a non-zero mass and nonzero moment of inertia We will discuss the operation of an Atwood machine with a pulley that has a non-zero mass […]

## Center of Mass of a system and its velocity – definition & equation

In this post, we will discuss the Center of Mass and its Momentum & velocity. Center of mass – for a single object & for collection of masses The center of mass (CM) is closely related to the concept of momentum. In most of the discussions and numerical problems, we assume that the various objects […]

## MCQ worksheet on Laws of Motion & different types of force (for grade 9 or class 9)

This post presents an MCQ worksheet with multiple choice questions taken from the chapters (a) Laws of motion & (b) Force of different types. This is useful for Class (grade) 9 and 10 students of different boards like CBSE, ICSE, IGCSE, etc. Laws of Motion & force – MCQ worksheet (physics) 1 ) First law […]

## Deriving the equation of Centripetal acceleration (using trigonometry)

In this post, we will derive the equation of centripetal acceleration using trigonometry. In a different post, we have done the derivation of the equation of centripetal acceleration using differential calculus. How to derive the equation of Centripetal acceleration (using trigonometry) In the above figure (figure 1), a particle is moving in a circle with […]

## Ways to Reduce Friction & Ways to Increase Friction

We need to reduce or increase friction in different situations, depending on our requirements and benefits. Here, in this post, we will list down some efficient ways to reduce friction. Not only that, but we will also come up with some intelligent ways to increase friction as well to make our life better. Ways to […]

## Tension force in a string – class notes

A lot of problems we discuss involve ropes and strings. Most of the time, we assume that they are massless, or more precisely, that the mass of a string is much smaller than the other masses in the problem. As you know from everyday life, if you grab a weight by a string, you feel […]

## Newton’s third law from the equation of conservation of linear momentum

In this post, we will see how Newton’s third law can be derived from the equation of conservation of momentum. Derive Newton’s third law from the equation of conservation of linear momentum Say, a body of mass m1 with velocity u1 collides with another body of mass m2 with velocity u2. After the collision, say, […]

## Common forces – types, definition & examples

In this post, we will discuss 8 common forces we find in Physics. For every such force type, we will find out the cause or reason or source of the force and also will site a few examples. The common forces we include are (1) weight, (2) Normal contact or normal force, (3) Friction, (4) […]

## Uniform circular motion

In this post, we will cover a bunch of questions and equations from the Uniform Circular motion chapter. When a particle moves in a circle with constant speed, the motion is called uniform circular motion. Examples of uniform circular motion: A car rounding a curve with a constant radius at a constant speed, a satellite […]

## Shape change by Forces & stretching a spring

Let’s discuss the application of forces to change the shape of an object and the concept of elasticity related to this shape change. We will cover the stretching of spring as a case study. If one force only is applied to an object then the object will change speed or direction. If we want to […]

## Derive formulas of centripetal force & centripetal acceleration

In this post, we will derive formulas of centripetal acceleration & centripetal force while we discuss the uniform circular motion. Uniform circular motion & its acceleration An object moving with uniform circular motion moves along a circular path of fixed radius at a constant speed. Since the direction of motion of the object is constantly […]

## Numerical problem on car hydraulic braking – solving

In this post, we will solve a numerical problem based on the principle of a car hydraulic braking system. To solve this numerical, we will take the help of the concepts of the lever, and the pressure principle of Pascal. We will go through the problem statement first and then solve the numerical step-by-step. Numerical […]

## 3 Types of collisions & their basic differences

In this post, we will list down the differences among the 3 primary types of collisions, elastic, inelastic & perfectly inelastic collisions. Among these types of collisions, elastic and perfectly inelastic collisions are limiting cases; most collisions actually fall into a category between these two extremes. In this third category of collisions, called inelastic collisions, […]

## How is Pulley a kind of lever?

A pulley is a grooved wheel with a rope, chain, or cable running along the groove. A pulley can change the direction of the input force or increase the output force, depending on whether the pulley is fixed or movable. A system of pulleys can change the direction of the input force and make the […]

## Applications of Impulse to improve safety – physics notes

Improving safety and reducing injuries is a critical application of impulse. In many cases, an object must be brought to a complete stop from a given initial velocity. This indicates that there is a specific change in momentum. If the time taken for momentum to change is increased, the force that must be applied is […]

## How to solve leaning ladder equilibrium numerical?

In this post, we will solve a numerical problem based on the equilibrium of a leaning ladder. To do this you need to first understand the conditions of equilibrium. If you require some revision then you can quickly go through our physics tutorial on the equilibrium conditions first, before attempting this numerical. Anyways, let’s begin […]

## Different types of Pressure gauges & how they operate

Pressure gauges measure the pressure exerted by a fluid, in other words by a liquid or a gas. We will cover 3 types of pressure gauges here, and these are known as (a) Bourdon gauge (b) U-tube manometer and (c) Mercury barometer. Let’s see how these pressure gauges operate. Bourdon gauge In a Bourdon gauge […]

## How to use Pascal’s law to explain Hydraulic car brakes?

Pascal’s Law states that any change in the pressure applied to a completely enclosed fluid is transmitted undiminished to all parts of the fluid and the enclosing walls. Let’s see how Pascal’s principle is applied to design hydraulic car brakes. When the brake pedal is pushed, the piston in the master cylinder exerts a force […]

## Measurement of coefficients of friction

This post discusses a typical experimental setup for the Measurement of coefficients of friction. As you well know, it’s easier to push an object from one point to another than to carry it from one point to another. We usually just accept this observation as obvious. But why is this so? The observation leads to […]

## Car safety, momentum & force – GCSE Physics

Car safety, momentum & force – GCSE Physics – The force on a person in a car crash can be very large and the force can be worked out from the deceleration in a crash. You can also work out the force in a crash using the equation for momentum. Car safety is designed using the concept of momentum and force related to a car crash. The objective is to keep the force on a person as small as possible. Let’s take an example of a car travelling a steep road.

## How to find out the Mechanical Advantage of Pulley | MA & IMA pulley

Of all simple machines, the mechanical advantage is easiest to calculate for pulleys. To find out the mechanical advantage of a Pulley, simply count the number of ropes supporting the load. That is the IMA or Ideal Mechanical Advantage of Pulley. Once again we have to exert force over a longer distance to multiply force. To […]

## Racecar tires versus passenger car Tires – The Physics of Car Tires (based on Friction) | Slick Tyre vs. Road Tyre – based on frictional force

You must have noticed that the racing car tires are made of rubbers, but without any treads. But why is it so? To answer this we have to compare Racecar tires and passenger car tires with the help of the Physics of Car Tires (based on Friction).In other words, we will discuss the topic: Road […]

## Bearings to reduce friction and increase the efficiency of devices

There are different ways to reduce friction. One way to reduce friction and increase the efficiency of devices such as generators, motors, and fans is to use bearings. Bearings are devices that allow surfaces to slide or roll across each other while reducing the force of friction. Many different types of bearings can be used […]

## How do Running shoes increase the force of static friction exerted by the ground on the athlete?

This post gives a preliminary idea of how physics fundamentals like friction and Newton’s laws of motion are involved in the design aspects of running shoes. Nowadays when sports have become so competitive, a pair of running shoes efficiently designed can bring a huge improvement in the performance of a runner. Here we will see […]

## Solving Numerical Problems involving Frictional Force or friction – for class 11

Here we will focus on solving numerical problems involving frictional force or friction and friction coefficient. We will take up a few sample problems as examples and solve those using the step-by-step process.