# What is energy class 2nd?

Energy is the ability to do work and a very important part of how we live. There are different types of energy like potential energy, kinetic energy, light energy, electrical energy, and even solar energy! For example, plants use energy from the sun to grow.

## What is work and energy formula?

Work can be calculated by multiplying Force and Distance in the direction of force as follows. W = F × d. Unit. The SI unit of work is the Joule (J)

## What is Ke formula?

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

## What is the correlation between work and energy?

The relationship between work and Kinetic Energy, also called the Work-Energy theorem, states that the work done by the sum of all the force acting over any particle/ object is equal to the change in the Kinetic Energy of the particle.

## What are the 3 formulas for work?

Mathematically, the concept of work done W equals the force f times the distance (d), that is W = f. d and if the force is exerted at an angle θ to the displacement, then work done is calculated as W = f . d cos θ.

## How do we calculate energy?

E = P*(t/1000); where E = energy measured in Joules or kilowatt-hours (kWh), P = power units in watts, and t = time over which the power or energy was consumed.

## How do u calculate kinetic energy?

1. Find the square of the velocity of the object.
2. Multiply this square by the mass of the object.
3. The product is the kinetic energy of the object.

## Is KE equal to PE?

PE = KE v = 4.6 m /sec the height is always the vertical distance (not necessarily the total distance the body may travel) between the starting point and the lowest point of fall. Nearly all mechanical processes consist of interchanges of energy among its kinetic and potential forms and work.

## What are the 2 main forms of energy?

Many forms of energy exist, but they all fall into two basic categories: Potential energy. Kinetic energy.

## What are 4 common types of energy sources?

The primary sources of energy in the environment include fuels like coal, oil, natural gas, uranium, and biomass. All primary source fuels except biomass are non- renewable. Primary sources also include renewable sources such as sunlight, wind, moving water, and geothermal energy.

## What are 10 uses of energy?

• electricity—all types of energy end uses.
• natural gas—space and water heating, clothes drying, cooking.
• heating oil—space and water heating, clothes drying.
• LPG/propane—space and water heating, clothes drying, cooking.
• kerosene—space heating.

## What is the difference between work and energy explain with an example?

Work is the transferring of an amount of energy with the help of a force covering a particular distance in a direction. Energy is also referred to as the force that works at a certain distance. Both of these can be termed scalar units. For work to occur, there must be a force and movement from one place to another.

## What is the relation between work and energy explain with two examples?

Lifting a weight from the ground and putting it on a shelf is a good example of work. The force is equal to the weight of the object, and the distance is equal to the height of the shelf (W= Fxd). Work-Energy Principle –The change in the kinetic energy of an object is equal to the net work done on the object.

## How do you know if work is positive or negative?

Work can be either positive or negative: if the force has a component in the same direction as the displacement of the object, the force is doing positive work. If the force has a component in the direction opposite to the displacement, the force does negative work.

## Is work scalar or vector?

Work has only a magnitude but no direction. The formula for work is written as a dot product of force and displacement. Therefore, work is a scalar quantity.

## What is the unit for work?

Scientists use the joule to measure work. One joule is equal to the work done by a force of one newton to move an object one meter in the direction of the force.

## Why cos theta is used in work?

The horizontal component is found by multiplying the force F by the cosine of the angle between F and d. In this sense, the cosine theta in the work equation relates to the cause factor – it selects the portion of the force that actually causes a displacement.

## What unit is energy?

Joule (J). This is the basic energy unit of the metric system, or in a later more comprehensive formulation, the International System of Units (SI). It is ultimately defined in terms of the meter, kilogram, and second.

## What is formula of work done?

To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd. If the force is being exerted at an angle θ to the displacement, the work done is W = fd cos θ.

## What does Q stand for in physics?

Big Q represents the source charge which creates the electric field. Little q represents the test charge which is used to measure the strength of the electric field at a given location surrounding the source charge. Give considerable attention to the charge quantity – Q or q – being used in each equation.

## Can potential energy negative?

Reason : Potential energy is always negative and if it is greater than kinetic energy total mechanical energy will be negative.

## How do you solve for velocity?

Velocity (v) is a vector quantity that measures displacement (or change in position, Δs) over the change in time (Δt), represented by the equation v = Δs/Δt.

## How do you find velocity with kinetic energy?

In classical mechanics, kinetic energy (KE) is equal to half of an object’s mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.

## What unit is PE in?

SI unit of potential energy is Joule (J).

## Is GPE equal to KE?

At terminal velocity, the rate of energy transfer for those two processes (GPE ==> KE, and KE ==> air) are equal; GPE is transforming into KE, and KE is transforming into energy of the air at the same rate, which is why speed stops increasing.