Force and Motion ( Chapter P10) Flashcards
what is the speed of sound
330m/s
What is non-uniform motion?
Non uniform motion is motion in which the speed is not constant.
What is the difference between speed and velocity?
Speed is a scalar quantity so only has a magnitude
Velocity is a vector quantity so has a magnitude and
direction.
What is the difference between distance and displacement?
Distance is the length of the total journey
Displacement is the straight line distance between the start and end points of a journey.
Distane is a scalar
Displacement is a vector
What is the equation for average velocity?
Average velocity = displacement / time
What is acceleration?
Acceleration is the rate at which an object’s velocity changes.
The unit of acceleration is m/s2
What is the equation for acceleration
Acceleration = change in velocity / time
What is Newton’s first law?
Newton’s first law tells us that if no resultant force acts on an object then that object’s motion will not change; it will either remain stationary, or if it is already moving, then it will carry on moving at a steady speed.
If there is a resultant force acting on an object then the object’s motion will change: it will accelerate.
What is Newton’s second law?
The acceleration of an object is directly proportional to the resultant force acting on it and inversely proportional to the mass.
What is the equation for force
Force = mass x acceleration
What is inertial mass?
Inertial mass is a measure of how difficult it is to change an object’s velocity.
It is defined as the resultant force acting on an object divided by the acceleration that force generates.
What is stopping distance?
Stopping distance is the total distance required to stop a moving vehicle.
What is thinking distance?
the distance travelled whilst reacting to a hazard.
What is the equation for stopping distance
= thinking distance + braking distance
What is braking distance
the distance travelled whilst the brake pedal is pressed.
