Motion Flashcards
What is Newton’s first law?
“A body remains at rest or in a state of uniform motion in a straight line unless it is acted on by an applied force.”
What is Newton’s second law?
“The time rate of change of the linear momentum of a body is equal to the force F applied to it.”
How is Newton’s second law expressed in mathematical terms?
F = ma Force = mass x acceleration
What is Newton’s third law?
“For every action, there is an equal and opposite reaction.”
What is translational motion?
The motion of a body in which all parts of the body have the same velocity and acceleration.
What is pure rotational motion?
Motion in which the rate of change in the angle is the same for all parts of the body but the velocity and acceleration along the body depend on the distance from the centre of rotation.
What forces are acting on a jumper during vertical jump?
Weight of the jumper (W) which is the downward force and the reaction force (F) which id the upward motion.
How is the net upward on the jumper expressed?
F - W
How is the acceleration of the jumper expressed mathematically?
a = F - W/(W/g) W = weight of jumper g = gravitational acceleration
What is the equation for calculating height of the jump?
H = (F-W)c/W
What is the velocity at the full height of the jump?
Zero
What is the weight of an object dependent on?
The mass and size of the planet on which it is located.
What is metabolic rate?
The energy consumed per unit time.
How is work done during a vertical jump calculated?
Weight x height of jump
What is the simplest angular motion?
One in which the body moves along a curved path at a constant angular velocity.
When would a car begin to skid?
When the centrifugal force is greater than the frictional force.
What forces act on the foot of a runner?
An upward force which supports the athletes weight and a centrifugal force which counteracts the centrifugal force.
When would a car begin to skid?
When the centrifugal force is greater than the frictional force.
What forces act on the foot of a runner?
An upward force which supports the athletes weight and a centrifugal force which counteracts the centrifugal force.
What is the back and forth movement of a pendulum called?
Harmonic movement.
What is the number of times the pendulum swings back and forth called?
The frequency.
What is the period of a pendulum?
The time for completing one cycle of the motion.
When is a pendulum’s energy entirely potential?
At the extreme of the swing
What happens to the energy of a pendulum as it is accelerated towards the centre?
Its velocity increases and the potential energy is converted to kinetic energy.
When is the velocity of a pendulum at its maximum?
When the pendulum passes the centre position.
When is a pendulum’s energy entirely kinetic?
When it passes the centre point.
What is the gravitational acceleration on Earth?
9.8 m/sec^2
How is gravitational force calculated?
F = mg g = gravitational acceleration
