joule, unit of work or energy in the International System of Units (SI); it is equal to the work done by a force of one newton acting through one metre. Named in honour of the English physicist James Prescott Joule, it equals 107 ergs, or approximately 0.7377 foot-pounds.

**Table of Contents**show

## What is work and energy in physics class 9?

Work done on an object is defined as the magnitude of the force multiplied by the distance moved by the object in the direction of the applied force. Work done = force × distance. = F × s. 1 Joule = 1 Newton × 1 metre. The unit of work is joule.

## What are the formulas of work and energy Class 9?

Work done by a force acting on an object is equal to the product of the force (F) and the displacement(s) of the object in the direction of the force, i.e., W = F × s = Fs.

## What is the SI unit of work and energy Class 9?

The SI unit of work and energy is Joule.

## How do you solve work and energy problems in physics?

## What is the SI unit of power?

unit of power is watt (W). When a body does work at the rate of 1 joule per second, its power is 1 watt.

## What is the SI unit of energy?

The SI unit of energy is same as that of work, which is joule (J).

## 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.

## What is energy formula?

Energy formula Physics: The formula for the Kinetic energy of an object is – K.E = ½ mv. The formula for the Potential energy of an object is – P.E = mgh.

## Is joule a SI unit?

The SI unit for work and energy commonly used in drawing is the joule (J), which is equivalent to a force of one newton exerted through a distance of one meter (m).

## Is joule a unit of heat?

Generally, all forms of energy are measured in terms of joules in the SI system. Notably, heat is a form of energy, and therefore the SI unit of heat is also joules (J) which are defined as the amount of energy needed to raise the temperature of a given mass by one degree.

## Is energy a vector or a scalar?

Energy is a scalar quantity as it has only magnitude.

## Is energy a vector?

They are actually derived from vector quantities of force and displacement by taking their scalar product. Hence, the correct answer is that energy is NOT a vector quantity.

## What is efficiency formula?

You can measure it by using the following formula: Efficiency = Output ÷ Input. Output (or work output) is the total amount of useful work completed without accounting for any waste and spoilage. If you want to express efficiency as a percentage, simply by multiplying the ratio by 100.

## Is time a energy?

Time is not directly related to energy itself, but it is definitely related to many aspects of energy. For example, the direction of time (from past to future) can be determined by the flow of energy in the universe. This concept is known as entropy.

## Is stress a unit?

Ans: The unit of stress is pascal or N/m2.

## Is KW a SI unit of power?

In SI system, unit of power is Watt (W). Kilowatt is equal to one thousand (103) watts. The kilowatt-hour is a unit of energy and is equal to 1,000 watt-hours.

## 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.

## Is joule CGS or MKS?

Unit of Energy in MKS System The MKS stands for meter-kilogram-second. 1 Joule is equivalent to one Newton-meter (N-m) where 1 J is the amount of work done by a newton of force to a distance of 1 meter.

## How is power measured?

Electricity is measured in Watts and kilowatts Electricity is measured in units of power called Watts, named to honor James Watt, the inventor of the steam engine. A Watt is the unit of electrical power equal to one ampere under the pressure of one volt. One Watt is a small amount of power.

## What is the example of zero work?

1) A simple example of zero work is when you stand holding a bag in your hands and do not move it. Your hands apply a force on the bag to balance the force of gravity exerted on it but since there is no displacement of the bag, the work done on it by you (your force) and also the gravity is zero.

## Is weight a force?

Weight is a force that acts at all times on all objects near Earth. The Earth pulls on all objects with a force of gravity downward toward the center of the Earth.

## What is dimension of energy?

Or, E = [M] × [L1 T-1]2 = M1 L2 T-2. Therefore, energy is dimensionally represented as M1 L2 T-2.

## Is heat a form of energy?

Thermal energy, or heat, is the energy that comes from the movement of atoms and molecules in a substance. Heat increases when these particles move faster. Geothermal energy is the thermal energy in the earth. Motion energy is energy stored in the movement of objects.

## Is work a vector?

Work is not a vector quantity, but a scalar quantity.