Newton's Laws Flashcards
What is Acceleration?
Acceleration is the rate of change of the velocity of an object with respect to time.
Accelerations are vector quantities (in that they have magnitude and direction).
What is the SI Unit for acceleration?
meter per second squared.
What is Inertia?
The resistance of any physical object to any change in its velocity. This includes changes to the object’s speed, or direction of motion.
What is inertia mostly affected by on the earth’s surface and what do these affects tend to decrease?
by gravity and the effects of friction and air resistance. All of which tend to decrease the speed of moving objects (commonly to the point of rest).
What is Newton’s first Law?
An object at rest stays at rest and an object in motion will continue with constant speed and direction unless acted upon by an unbalanced, external force.
What’s Newton’s second Law?
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
What’s the equation for Newton’s second Law?
F = M x A
Which is
Force = Mass x Acceleration.
Side note:
Because the Force required is the Mass of the Object multiplied by the Acceleration.
What is newton’s third law?
For every action there is an equal and opposite reaction.
A fly splats itself onto the windscreen of a bus that is travelling at 60 km/h. Which force is greater?
A. Each force is Equal
B. The Bus
C. Neither the bus or the fly are accelerating.
D. The Fly
A. Each force is equal
This is why:
Neither the bus or the fly are accelerating until the impact. Where F = M x A applies is the acceleration of each object after the impact. The result will be that the fly’s deceleration (a form of acceleration, just negative) will be substantially greater than the bus because of the significant difference in mass. The forces involved are equal.
