If a particle is moving, it has kinetic energy. Kinetic energy is the energy of motion, and it depends on the speed and mass of the particle. It is given by the formulaEk = -1/-mv²,where Ek is the kinetic energy, m is the mass, and v is the speed of the particle.The formula for kinetic energy has some important features to keep in mind.• Kinetic energy, and every other type of energy as well, is a scalar quantity, given by only a single number. Energy does not have a "direction", unlike a vector quantity. (This is incontrast to the vector quantity momentum, which you might have already studied.)• Kinetic energy, in particular, is always a positive number. (Note the speed v is the magnitude of the vector velocity, and therefore is positive. But even if it were a negative number,squaring it would always lead to a positive result.)• Kinetic energy depends on the square of the speed. (This is in contrast to the magnitude of momentum, mv, a quantity you may have already studied, which depends on the speedalone.) This means that doubling a particle's speed will quadruple its kinetic energy.When using SI units, the units of energy work out to be kg m²/s². This unit is given its own name, the joule, symbol J. To get a sense for how large a joule is, let's calculate a few examples ofkinetic energy.A student with a mass of 58.0 kg is walking at a leisurely pace of 1.80 m/s. What is the student's kinetic energy (in J)?A typical baseball has a mass of 0.145 kg. Some pitchers can throw a baseball with a speed of about 102 miles per hour, or about 45.6 m/s. What is the kinetic energy (in J) of a typical baseballmoving at this speed?

Kinetic energy of object having mass m and speed v is given asEk = 12mv2Mass of student m= 58 kgspeed of student v = 1.8 m/sUsing these values Ek = 12×(58 kg)×(1.8 m/s)2 Ek =93.96 (kg·m2/s2)Ek =93.96 JMass of baseball m =0.145 kgspeed of baseball v = 102 miles per hour = 45.6 m/susing these values kinetic energy will beEk = 12×(0.145 kg)×(45.6 m/s)2 Ek =150.75 (kg·m2/s2)Ek =150.75 J Answer : Kinetic energy of student is 93.96 J Kinetic energy of baseball is 150.75 J

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A student with a mass of 58.0 kg is walking at a leisurely pace of 1.80 m/s. What is the student's kinetic energy (in J)? A typical baseball has a mass of 0.145 kg. Some pitchers can throw baseball with a speed of about 102 miles per hour, or about 45.6 m/s. What is the kinetic energy (in J) of a typical baseball moving at this speed?

A student with a mass of 58.0 kg is walking at a leisurely pace of 1.80 m/s. What is the student's kinetic energy (in J)? A typical baseball has a mass of 0.145 kg. Some pitchers can throw baseball with a speed of about 102 miles per hour, or about 45.6 m/s. What is the kinetic energy (in J) of a typical baseball moving at this speed?

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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