Lecture 1: Forces and Newton's laws

When emailing the lecture-note toimechanica@gmail.comwith the subject title as Lecture 1, please also put your information in the text message: Name, University ID, and Aerospace/Mechanical Engineering. Thanks.

1. Aforceis a relationship
2. A force is avector

Newton's laws of motion

3rd law

For every action, there is an equal and opposite reaction.

2nd law

Force is a vector,F
Acceleration is a vector,a
F=ma

Galileo’s experiment
Leaning tower of Pisa
No matter what the difference in weight, two heavy objects will fall simultaneously at virtually the same speed
Experiment: drop of two objects with different masses
Resistance from air

a=F/m
Massive the object, more tends to resist changes in its state of motion
Gladiator
helmet(design issue, protection and mobility)

1st law

An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

• Car & wall. Why the guy rotates around itself when being hurled into the air?
• Truck & ladder
• Blood rush; Tighten the head of a hammer

back toMACE-11010 Engineering Mechanics
back toMACE-11010 Calendar