Ch2 Physics summary
2.1 Types of forces
You can’t see forces, but you can see the effects they have on the physical world.
1. Change in speed
2. Change in direction of motion
3. Deformation (shape). (elastic deformation when it returns to its prior form and
plastic deformation when it doesn’t.)
Types of forces=
1. Muscular strength (Fmuscle)
2. Spring resistance (Fspring)
3. Force of gravity (Fg)
4. Tension (Ftension)
5. Friction (Ffriction)
Force is abbreviated with F and we measure it in newtons(N)
You can calculate the force of gravity on an object by the following formula; F g=m∙ g
M= mass of the object, measured in kilograms (kg)
G= = the gravitational constant (Earth; g = 9.81 N/kg.)
A vector is a physical quantity which has a direction.
When measuring force vectors, use the included force scale to determine the true
magnitude of the force vector.
When drawing a force as a vector, you have to go through three steps;
1. The point of application of the force
2. The direction of the force
3. The length (magnitude) of the arrow
2.2 More than one force
Forces work along an imaginary line, the so-called line of action.
Forces facing the same way on the same line of action can be added to each other.
Forces facing the opposite way on the same line of action can be substracted from each
other.
The remaining net force is called the ‘resultant force’ (Fres)
The force of gravity is balanced by the normal force (Fn).
When Fres equals 0 N, we say that the object is ‘in equilibrium’.
When the force on a spring doubles, the extension doubles as well. We call this relation
‘directly proportional’.
F spring
C= (x is extension, c is spring constant)
x
Parallelogram method= used when 2 forces are facing very fifferent directions. Draw a
parallel dotted line for each vector, plot the points where they intersect and measure the
length and use the scale.
2.3 Driving forces and resisting forces
2.1 Types of forces
You can’t see forces, but you can see the effects they have on the physical world.
1. Change in speed
2. Change in direction of motion
3. Deformation (shape). (elastic deformation when it returns to its prior form and
plastic deformation when it doesn’t.)
Types of forces=
1. Muscular strength (Fmuscle)
2. Spring resistance (Fspring)
3. Force of gravity (Fg)
4. Tension (Ftension)
5. Friction (Ffriction)
Force is abbreviated with F and we measure it in newtons(N)
You can calculate the force of gravity on an object by the following formula; F g=m∙ g
M= mass of the object, measured in kilograms (kg)
G= = the gravitational constant (Earth; g = 9.81 N/kg.)
A vector is a physical quantity which has a direction.
When measuring force vectors, use the included force scale to determine the true
magnitude of the force vector.
When drawing a force as a vector, you have to go through three steps;
1. The point of application of the force
2. The direction of the force
3. The length (magnitude) of the arrow
2.2 More than one force
Forces work along an imaginary line, the so-called line of action.
Forces facing the same way on the same line of action can be added to each other.
Forces facing the opposite way on the same line of action can be substracted from each
other.
The remaining net force is called the ‘resultant force’ (Fres)
The force of gravity is balanced by the normal force (Fn).
When Fres equals 0 N, we say that the object is ‘in equilibrium’.
When the force on a spring doubles, the extension doubles as well. We call this relation
‘directly proportional’.
F spring
C= (x is extension, c is spring constant)
x
Parallelogram method= used when 2 forces are facing very fifferent directions. Draw a
parallel dotted line for each vector, plot the points where they intersect and measure the
length and use the scale.
2.3 Driving forces and resisting forces
