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

Science

Physics

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)...

See similar textbooks

Similar questions

A typical baseball has a mass of 0.145 kg. Some pitchers can throw a baseball with a speed of about 103 miles per hour, or about 46.0 m/s. What is the kinetic energy (in J) of a typical baseball moving at this speed?
A 35.0 kg man climbs a 6.0 m ladder. What is the potential energy of the man when he reaches the top of the ladder?
The roadrunner has a mass of 25.0 kg. He runs around the desert valley at 3.28 m/s. What is his kinetic energy?
The kinetic energy of a moving object is KE = 1/2 mv2, where m is the mass and v is the speed. An average apple has a mass of 0.22 kg. How fast must the apple travel in m/s to have kinetic energy of 0.59 million joules?
A car travelling at a speed of 60 km/h has a kinetic energy of 200 kJ. If the speed of the car is increased to 120 km/h, the kinetic energy of the car will be а. 200 kJ O b. 400 kJ Ос. С. 100 kJ O d. 800 kJ
Q01
A ball has a total energy of 140 J when it is dropped from rest from a height of 20 meters. Assuming energy is conserved, when the ball is 5 meters above the floor: Q1: What is the total energy of the ball? Q2: What is the potential energy of the ball? Q3: What is the kinetic energy of the ball? Q4: If air friction cannot be ignored, how will the potential energy and the kinetic energy of the ball at 5 meters be affected?
The roadrunner has a mass of 25.0 kg. He runs around the desert valley at 3.00 m/s. What is his kinetic energy A J
A child does 350 J of work while pulling a box from the ground up to his tree house with a rope. The tree house is 7.4m above the ground. What is the mass of the box?
Physics Question
A cart is pulled at a constant speed along an inclined plane to the height of a seat top. If the mass of the cart is 3.8 kg and the height of the seat top is 0.53 meters, what is the potential energy of the cart at the height of the seat-top?
A student is riding a bicycle at a constant speed of 4.36 m/s on a level road. The mass of the student and bicycle together is 76.5 kg. Assume the friction and drag is 40.6 N. What is the student's metabolic power, in Watts? Use g = 10.0 m/s2.