P8 - Forces In Balance Flashcards
What is Distance?
Distance is the length travelled
What is displacement?
Displacement is distance without change of direction. In other words displacement is the distance in a given direction.
What is a Scalar quantity?
A scalar quantity is magnitude without direcrion
What is a vector quantity?
A vector quantity is magnitude with direction.
Give an example of a scalar quantity.
Distance, speed, time, mass, energy and power
Give an example of a vector quantity
Acceleration, force, momentum, weight and gravitational field strength
How is a vector quantity represented?
The direction of the arrow represents the direction of the vector quantity. The length of the vector quantity represents the magnitude of the vector quantity.
What is a force?
A force is a push or a pull that acts upon an object due to its interaction with another object.
What are forces measured in?
Newtons, N
Give some examples of what a force can do to an object?
It can change the shape of am object, start or stop it moving, or change its direction.
What is a contact force?
A contact force is a force that requires 2 or more objects to physically touch each other to occur
What is a non contact force?
A non contact force is a force that acts upon an object without coming physically in contact with it.
Give some examples of a contact force.
Friction, air resistance, water resistance and tension
Give some examples of non-contact forces
Magnetic force, electrostatic force and gravity.
What is Newtons third law of motion?
When 2 objects interact with each other, they exert equal and opposite forces on each other.
Give an 2 examples of newtons third law of motion in action
If a boxer punches a bag with a force of 100N, he will experience an equal and opposite force of 100N.
If a rocket exerts a force of 1 Million Newtons downwards it will experience an equal and opposite force of 1 Million Newtons pushing it upwards.
What is driving force.
Driving force is the force from the tyre of a car pushing backwards on the floor, when a car is driving
What is the equal and opposite force to driving force?
Friction from the ground
What is resultant force?
If an object has more than 1 force acting upon it then the resultant force of the object is the single force that has the same effect as all the forces acting upon the object.
What is newtons first law of motion?
If the forces acting upon an object are balanced the resultant force is zero and therefore:
°If the object is at rest it will stay at rest.
°If the object is in motion it will stay in motion.
(Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an unbalanced force)
How do you find the resultant force of 2 forces going in the same or opposite directions?
If the forces are going in the same direction you add the forces to find the resultant force and if they are going in opposite directions you subtract the smaller force from the larger force.
What is the line of action of a force?
The line of action is the line that the force acts along
What is equilibrium? (forces)
Equilibrium is when the resultant force on the object is 0
What is the centre of mass?
The point at which its mass can be thought of as being concentrated
What is a load?
the weight of an object raised by a device used to lift the object, or the force applied by a device when it is used to shift an object
What is friction?
the force opposing the relative motion of two solid surfaces in contact
What is a free-body diagram?
a diagram that shows the forces acting on an object without any other objects or forces shown
What is a force multiplier?
a lever used so that a weight or force can be moved by a smaller force
What is a parallelogram of forces?
a geometrical method used to find the resultant of two forces that do not act along the same line
What is the principle of moments?
When an object is not moving: the sum of all the clockwise moments about any point = the sum of all the anticlockwise moments about that point
How do you perform the paralleogram of forces?
Use a compass to find the bisector of the 2 forces and the resultsnt force will be from the source point to the bisected point
What type of force is electrostatic?
non-contact
What is the downward force on a body known as?
Weight
