Forces Flashcards
Friction, weight, mass, moment, elastic and inelastic
What is a force?
This is a push or pull, which one object applies to another
Is a force a vector or scalar quantity?
A force is a vector quantity
What are the two types of forces?
Contact and non-contact forces
What are contact forces?
When forces are joined together or in contact
What are non-contact forces?
When forces act over a distance without any direct connection
What is the region over which non-contact forces act are called
These are called fields
What are some examples of contact
Forces Tension Frictional forces Expansion force of compressed spring Expansion force of a heated object Upthrust force on a floating object Air resistance
What are some examples of non-contact forces
Gravitation attraction between the earth and the moon
Magnetic fields of magnets and elastic currents
Weight
What are some frictional forces
- are a reaction to other forces
- oppose of motion
- cause wear and damage
- generate heat and waste energy
Cause of friction
Friction is caused by points of contact on the surface obstructing movement, and by molecular forces of attraction at the points of contact
What are some ways of reducing friction?
- make surfaces smoother
- use a lubricant such as oil or grease
- use wheels or rollers
- fit ball- bearings on axles
- streamline shapes of vehicles
What is the mass of an object?
The mass of an object is a measure of the matter in it and depends on the number of atoms it contains and the size of the atoms
What is the weight of an object,?
The pull of the earth on an object
1grams is how much newton’s?
0.01 N
1/100
100 grams when converted to Newtons?
1 Newtons
100/100
1kg converted to N
10 Newtons
1000g/100
10 kg converted to Newton
100 Newtons
10,000g/100
A block of wood has a mass of 340g, what is its weight?
340g =0.340kg
0.340kg ×10=3.4N
What is the formula for weight
W= mg
What is the gravitational field strength on Mars?
3.7 N kg–¹
What are antiparallel forces?
These are forces acting on opposite directions along the same straight line, the combined effect is found by subtracting their magnitudes
Two forces of 3N and 4N act at right angles at the same point on an object find by calculation their resultant forces? And angle
R² = F1² + F2²
= 3² + 4²
√R²= 9 + 12
R. = 5
Tan °= f1/ f2= 1.33
1.33×tan°= 53°
What is the moment of a force
This is the turning of a force, this depends on both the magnitude and how far away it is
What is the difference between Joules and Newton meter?
(J) the force and distance are in the same direction while calculating (Nm) the force is at right angles to the distance being measured
