P5 Forces Flashcards
Define the term vector
A vector has magnitude and direction
Whats a non-contact force ??
Objects that are physically separated
Whats a contact force ??
Objects that are physically touching
What happens to gravity when the mass increases??
The field gets stronger, mass gets larger and the attraction is greater.
What is the Formula used for weight
Weight= mass x grams
Explain the term resultant force ??
Resultant force is a single force representing the sum of all the forces acting on an object.
There are two forces on the falling skydiver - its weight and air resistance.
What causes the weight?
So the air resistance increases and the weight of the diver decreases.
What happens to the skydivers speed as he falls from the plane??
The divers speed increases as he goes down.
What is the meaning of work and the formula used
Where distance is distance moved along the line of action of the force. Work Done = Force × Distance
What is deformation ???
Deformation means changing shape
What is the Formula used for moments of a force??
Moment= force x perpindicular distance
Definiton of pressure
When Particles in a gas move randomly in every direction and they exert forces on their container, which is
felt as press
Explain the term upthrust
A partially submerged object experiences a greater pressure on the bottom surface than on the top surface. This creates a resultant force upwards which is known as upthrust.
What is displacement ???
Displacement includes both the distance an object moves, measured in a straight line from the start point to the nish point and the direction of that straight line. Displacement is a vector quantity.
Equation used for speed
Speed= distance/time
Which are the two diferrent graphs used for acceleration ??
Displacement-Time Graphs
Velocity time graphs
What are displacement time graphs??
The gradient of a velocity-time graph at a particular time gives the acceleration of the object at that time. The area under a velocity-time graph gives the displacement
What are velocity time graphs??
If an object moves along a straight line, its motion can be represented by a velocity-time graph. The gradient of the line is equal to the acceleration of the object
What is average speed??
when the speed changes during the motion
What is newtons first law??
An object has a constant velocity unless acted on by a resultant force.
What is newtons second law??
The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.
Force = mass x acceleration
What is newtons third law??
Whenever two objects interact, the forces they exert on each other are equal and opposite.
Eg- Rocket taking off
Explain Thinking distance and braking distance
Thinking distance- is the time it takes for you to activate your brakes.
Braking distance- refers to the distance a vehicle will travel from the point when its brakes are fully applied.
what is the formula used for stopping distance??
Stopping distance= thinking+Braking distances
Explain the term momentum and the formula used for it.
Momentum is always conserved in a collision or explosion (where there are no external forces like friction, air resistance, electrostatic attraction etc.)
Momentum= mass x velocity
