"Kinetic Energy and Kinetic Energy Theorem" Law of Conservation of Mechanical Energy PPT courseware

Description

"Kinetic Energy and Kinetic Energy Theorem" Law of Conservation of Mechanical Energy PPT courseware

Part One: Perceiving Kinetic Energy

What is the reason for the change in kinetic energy of these objects? How to express kinetic energy quantitatively?

theoretical inquiry

Scenario 1

On a smooth horizontal surface, an object with mass m undergoes a displacement l under the action of a constant force F that is always the same as the direction of motion, and the speed increases from v1 to v2. Try to find the relationship between the work done by the external force and the kinetic energy in this process.

Scenario 2

If the ground is rough and the friction force on the object is always f, what is the relationship between the work done by the external force and the kinetic energy in this process?

1. How much work does an external force do on an object?

2. What is the object's acceleration?

3. What is the relationship between the initial velocity, final velocity and displacement of an object?

4. What relationship can be derived from the above three equations?

Kinetic energy and kinetic energy theorem PPT, part 2: knowledge construction

Kinetic Energy Kinetic Energy Theorem

1. Kinetic energy:

(1) Concept: the energy an object has due to its motion

(2) Size: Ek=mv2/2

(3) Unit: J 1J=1kg·m2/s2

(4) Kinetic energy is a scalar quantity and a state quantity

(5) Kinetic energy is relative and can only take positive values

object of constant mass

1. Does the kinetic energy necessarily change when the speed changes?

2. When kinetic energy changes, does the speed necessarily change?

2. Kinetic energy theorem: The work done by a force on an object during a process is equal to the change in kinetic energy of the object during the process.

3: Expression: work done by the resultant force, kinetic energy of the final state, kinetic energy of the initial state

4. Understand:

(1)Causal relationship: cause and effect

(2) Quantitative relationship: mutual demand for functions

(3) Identity: l and v are relatively the same reference system---usually choose the ground

Expand applications

[Example 1] The picture below shows the moment a bullet passed through an apple captured by a high-speed camera. The bullet's instantaneous speed before hitting the apple is about 900m/s, and the instantaneous speed when it passes through the apple is about 800m/s. The bullet's mass is about 20g, and the path it travels through the apple is about 10cm. Try to estimate the average impact of the bullet on the apple when it passes through the apple?

Summary: Steps to solve the kinetic energy theorem

1. Determine the object and select the process;

2. Analyze the force and calculate the total work;

3. Know the movement and determine the beginning and end;

4. Make equations and solve them carefully.

Kinetic energy and kinetic energy theorem PPT, part 3: Frequently asked questions

Question Group 1: Understanding of kinetic energy and changes in kinetic energy

Question 1 Regarding the understanding of kinetic energy, which of the following statements is correct ()

A. Kinetic energy is a basic form of ubiquitous mechanical energy. All moving objects have kinetic energy.

B. In the formula Ek= mv2, v is the speed of the object relative to the ground, and the kinetic energy is always positive.

C. For an object of a certain mass, when the kinetic energy changes, the speed will definitely change, but when the speed changes, the kinetic energy will not necessarily change.

D. An object with constant kinetic energy must be in equilibrium

Question 2: A small ball is thrown vertically upward from the ground. The ball moves for a period of time and then falls back to the ground. Ignoring air resistance, the relationship between the kinetic energy Ek of the ball and time t during this process is ()

Question 3 Regarding the relationship between work and changes in kinetic energy of an object, which of the following statements is correct ()

A. As long as a force does work on an object, the kinetic energy of the object increases.

B. As long as an object overcomes resistance and does work, its kinetic energy decreases.

C. Both power and resistance do work on the object, and the kinetic energy of the object must change.

D. The algebraic sum of the work done by a force on an object is equal to the difference between the final kinetic energy and the initial kinetic energy of the object.

Keywords: Free download of PPT courseware for high school physics compulsory course II of the People's Education Press, PPT download of kinetic energy and kinetic energy theorem, PPT download of the law of conservation of mechanical energy, .PPT format;

For more information about the "Law of Conservation of Mechanical Energy Kinetic Energy and Kinetic Energy Theorem" PPT courseware, please click on the "Law of Conservation of Mechanical Energy ppt Kinetic Energy and Kinetic Energy Theorem ppt" tag.

"Law of Conservation of Mechanical Energy" PPT:

"Law of Conservation of Mechanical Energy" PPT Part One Content: Foundation of Essential Knowledge Literacy 1. Mutual Conversion of Kinetic Energy and Potential Energy [Thinking] During the upward movement of trampoline athletes, how do the elastic potential energy of the trampoline, the gravitational potential energy and kinetic energy of the athletes transform into each other? carry..

"Kinetic Energy and Kinetic Energy Theorem" Law of Conservation of Mechanical Energy PPT:

"Kinetic Energy and Kinetic Energy Theorem" Law of Conservation of Mechanical Energy PPT Part One Content: Foundation of Necessary Knowledge Literacy 1. Kinetic Energy [Thinking] As shown in the picture, it is a chariot that attacks the city gate in ancient wars. The chariot is equipped with a circular cylinder with a large mass. Wood, there are many soldiers pushing chariots in a circle...

"Gravity Potential Energy" Law of Conservation of Mechanical Energy PPT courseware:

"Gravitational Potential Energy" Law of Conservation of Mechanical Energy PPT courseware Part One: Learning Objectives 1. Know that the work done by gravity has nothing to do with the path of motion. 2. Understand the concept of gravitational potential energy and be able to use the definition of gravitational potential energy to calculate. 3. Know that gravitational potential energy is relativistic..

File Info

Update Time: 2024-10-18

This template belongs to Physics courseware People's Education Press High School Physics Compulsory Course II industry PPT template

Preview