Flashcards
physics yr9
Cards in this deck (13)
- 1what is center of mass?In physics, the center of mass of a distribution of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero.
- 2how do you find an objects center of mass?The concept of the center of mass is that of an average of the masses factored by their distances from a reference point. In one plane, that is like the balancing of a seesaw about a pivot point with respect to the torques produced.
- 3how does an objects center of mass effect it when tilting?Objects with a wide base, and a low center of mass, are more stable than those with a narrow based and a high center of mass.
- 4How do you calculate the time period for a pendulum?T = time period in seconds, s
f = frequency in Hertz, Hz
- 5What is a simple pendulum?A plumb line is an example of a simple pendulum. This is a simple machine consisting of a weight (called a bob) suspended from a suspension point by a thin piece of material such as string or a chain. The bob should be free to swing.
- 6what are some common examples of every day pendulums?Common examples of pendulums include:
swings at playgrounds
some fairground rides - eg pirate ship rides
the inside mechanisms of some clocks and grandfather clocks
- 7What is circular motionIn physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation.
- 8What is terminal velocity?the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration.
- 9What is resultant force?A resultant force is the single force and associated torque obtained by combining a system of forces and torques acting on a rigid body. The defining feature of a resultant force, or resultant force-torque, is that it has the same effect on the rigid body as the original system of forces.
- 10what is the turning effect of a force called?the moment
- 11what must be balanced if an object is not turning?the clockwise and anticlockwise moment around the pivot
- 12when is work done?when a force causes an object to move through a distance
- 13when is something acting elasticity?when it returns to it's former shape after the force is taken away