Topic 5 - Forces Flashcards
(67 cards)
What is acceleration?
The rate of change of velocity. It can be calculated from the gradient of a velocity-time graph.
What is the definition of atmosphere?
The thin layer of air surrounding the Earth, which gets less dense
with increasing altitude.
What is braking distance?
The distance a vehicle travels under the braking force. This can be affected by adverse road and weather conditions as well as the condition
of the vehicle.
What is centre of mass?
The single point through which the weight of the object can be said to act.
What are changes in momentum?
When a force acts on a moving object, or one an
object that has the ability to move, a change of momentum will occur. The
force is equal to the rate of change of momentum.
What is the conservation of momentum?
The total momentum of a system before an event is always equal to the total momentum of the system after the event.
What are contact forces?
A force that occurs when objects are physically touching.
What is displacement?
A measure of how far an object moves in a given direction. It is the straight line between the starting and finishing points and is a vector quantity.
What is distance in physics?
A measure of how far an object moves, that does not depend on direction and is therefore a scalar quantity.
What is elastic deformation?
Non-permanent deformation which allows the object to return to its original shape when the deforming forces are removed.
What is elastic limit?
The force beyond which an object will no longer deform elastically, and will instead deform plastically.
What is elastic potential energy?
The energy stored in a spring when it is stretched or compressed, due to the work done on the spring by the deforming force. It is equal to the work done as long as the object does not plastically deform.
What is equilibrium?
An object is in equilibrium if the resultant force and resultant moment are both equal to zero.
What does floating mean in physics?
An object will float if the volume of liquid it displaces has a greater weight than that of the object itself. The upthrust acting on the object is greater than its weight.
What is a fluid?
A liquid or gas.
What are forces?
A push or pull that an object experiences due to the interaction with another object. Force is a vector quantity.
What is Inertia?
The tendency of an object to remain in its same state of uniform motion or rest.
What is inertial mass?
A measure of how hard it is to change an object’s velocity. It is defined as the ratio of force over acceleration.
What is limit of proportionality?
The point beyond which the extension of an elastic
object is no longer directly proportional to the force applied to it.
What is moment?
The turning effect of a force, equal to the product of the magnitude of the force and the perpendicular distance from the pivot to the line of action of the force.
What is momentum?
The product of an object’s mass and velocity.
What is a newton meter?
A calibrated spring-balance used to measure weight.
What is Newton’s first Law?
If a stationary object’s resultant force is zero, the object will remain stationary. If a moving object’s resultant force is zero, the object will
continue to move at the same speed, and in the same direction.
What is Newton’s second Law?
An object’s acceleration is directly proportional to the
force applied to it, and inversely proportional to its mass.