Exam 1 - Forces & Force Composition and Resolution

Question 1

Vectors

Answer 1

describe forces in size or magnitude and direction

length = magnitude
shaft = line of action and point of application
arrowhead = direction

Question 2

Internal Forces

Answer 2

• act within the object or system to change shape
• incapable of producing changes in COM (center of mass)
• muscles

Question 3

External Forces

Answer 3

• occur as a result of interaction with environment
• capable of producing changes in COM (center of mass)
• non-contact and contact forces

Question 4

Non-Contact Forces

Answer 4

Gravitational Force

weight (N) = mass * gravity

Question 5

Contact Forces

Answer 5

Normal Contact Forces

• normal reaction force
• perpendicular to surfaces

Friction

• parallel to surfaces
• opposes motion (occurs in opposite direction of motion)

*normal contact forces and friction inc. due to inc. in weight & in molecular interactions btwn contact surfaces

Question 6

Force Composition

Answer 6

takes several external forces and puts them together to figure out the resolution

result of forces combining
“resultant vector” or “..force”

Question 7

Force Resolution

Answer 7

takes the result & breaks them down into the individual forces

breaking resultant vector into its horizontal and vertical components

Question 8

Resultant Vector

Answer 8

result of vector addition of forces

represented by a resultant vector

Question 9

Colinear Forces

Answer 9

forces that have the same line of action

• forces are on the same line or plane at the same time but don’t have to go in the same direction
• tip to tail

Question 10

Resultant Force

Answer 10

found by drawing an arrow from the tail of the first force to the top of the last force

It is calculated by summing the forces

ex. tug of war

Question 11

Concurrent Forces

Answer 11

forces that occur at the same time but do not act on the same line, but they do act through the same point

Question 12

Pythagorean theorem

Answer 12

A2 + B2 = C2