An object of mass 40 kg is raised to a height of 5 m above the ground. what is its potential energy? if the object is allowed to fall, find its kinetic energy when it is half-way down.

• Login • Category • Java • JSP • iOS • HTML • Android • Python • C Programming • C++ Programming • C# • PHP • CSS • Javascript • jQuery • SAP • SAP HANA • Data Structure • RDBMS • MySQL • Mathematics • 8085 Microprocessor • Operating System • Digital Electronics • Analysis of Algorithms • Mobile Development • Front End • Web Development • Selenium • MongoDB • Computer Network • General Topics • Trending Categories • Data Structure • Networking • RDBMS • Operating System • Java • MS Excel • iOS • HTML • CSS • Android • Python • C Programming • C++ • C# • MongoDB • MySQL • Javascript • PHP • Physics • Chemistry • Biology • Mathematics • English • Economics • Psychology • Social Studies • Fashion Studies • Legal Studies • Selected Reading • • • • • • • Given: An object of mass $40\ kg$ is raised to a height of $5\ m$ above the ground. To do: To find its potential energy and If the object is allowed to fall, we have to find its kinetic energy when it is halfway down. Solution: Let us know the formula used for calculating the potential energy and kinetic energy of an object: Potential energy, $P.E.=mgh$ Kinetic energy, $K.E.=\frac\ m=2.5\ m$ So, its potential energy $P.E.'=mgh'=40\times9.8\times2.5=980\ J$ Then, the kinetic energy of the object $K.E.=Total\ energy-potential\ enrgy$ $=1960\ J-980\ J$ $=960\ J$ So, the kinetic energy of the object halfway down is $980\ J$.

Gravitational potential energy Any object lifted above the ground has gravitational potential energy ( \(E_\) is the gravitational potential energy in joules, J m is the mass in kilograms, kg g is the gravitational field strength in newtons per kilogram, N/kg h is the change in height in metres, m Question A book with a mass of 0.25 kg is lifted 2 m onto a bookshelf. If g is 10 N/kg, how much gravitational potential energy does it gain? Reveal answer down \(E_\) = 5 J The gravitational potential energy gained by the book is 5 J. Question A book of mass 600 g has 12 J of gravitational potential energy. How high is it above the Earth’s surface? (g = 10 N/kg)? Reveal answer down The book has mass 600 g. This must be converted into kg to use in the equation for gravitational potential energy. 600 g = \(\frac\) h = 2 m The book is 2 m above the surface of the Earth.

\( PE_g = mgh \) Where: • PE g or PE = gravitational potential energy • m = mass of an object • g = acceleration due to gravity • h = height of the object What Is Gravitational Potential Energy (GPE) Potential Energy is the stored energy of an object given its position relative to a body. Gravitational potential energy is one type of potential energy and is equal to the product of the object's mass (m), the acceleration caused by gravity (g), and the object's height (h) as distance from the surface of the ground (the body). In this example, a 3 kilogram mass, at a height of 5 meters, while acted on by Earth's gravity would have 147.15 Joules of potential energy, PE = 3kg * 9.81 m/s 2 * 5m = 147.15 J. 9.81 meters per second squared (or more accurately 9.80665 m/s 2) is widely accepted among scientists as a working average value for Earth's gravitational pull. This figure is based on a measure of gravity at sea level at a latitude of 45°. • At higher altitudes, gravity decreases slightly. • The effect of latitude on gravitational force is relevant as gravity increases with increasing distance from the Equator. At the Equator, the Earth's gravity is 9.780 m/s 2 and at the poles it is 9.832 m/s 2 (source: CRC Handbook of Chemistry and Physics). Gravitational acceleration (to three

Gravitational mechanical energy is given by the expression, \( W = mgh \) Where, h = Vertical displacement = 5 m, m = Mass of the item = 40 kg g = Acceleration because of gravity = 9.8 m s -2 \( \therefore W = 40 × 5 × 9.8 = 1960 \ J \) . At half-way down, the mechanical energy of the item are going to be \( \frac \) At this time, the item has an equal quantity of potential and K.E. This can be due to law of conservation of energy. Hence, half-way down, the K.E. of the item can be 980 J. NCERT solutions of related questions for Work and Energy • Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. (a) Suma is swimming in a pond. (b)A donkey is carrying a load on its back. (c) A wind-mill is lifting water from a well. (d) A green plant is carrying out photosynthesis. (e) An engine is pulling a train. (f) Food grains are getting dried in the sun. (g) A sailboat is moving due to wind energy. • An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object? • A battery lights a bulb. Describe the energy changes involved in the process. • Certain force acting on a 20 kg mass changes its velocity from 5 m/s to 2 m/s. Calculate the work done by the force. • A mass of 10 kg is at a point A on a table. It is moved to...