SP14- 15 Flashcards
What happens when a force acts on an object?
The object may change shape by bending, stretching or compressing- or a combination of all 3 shape changes.
What must there be to change the shape of a stationary object>
More than one force acting on the object to bend, stretch or compress it.
What is a change in shape called?
Distortion.
What can happen to elastic distortion?
It is reversed (goes back to its original state) when the force is removed.
What happens to inelastic distortion?
It is not fully reversed when the force is removed- there is a permanent change in shape.
When does extension happen?
When an object increases in length.
When does compression happen?
When an object decreases in length.
What does Hooke’s law state?
Force = spring constant x extension F= Kx K= spring constant.
What is the spring constant?
The force needed to produce an extension of 1m.
What happens the higher the spring constant?
The stiffer the spring.
What is extension directly proportional to?
The force applied.
What happens when an object is stretched beyond its limit of proportionality?
It does not return to its original length when the force is removed.
What is the equation to calculate elastic potential energy?
elastic potential energy=0.5 X spring constant X (extension)2
Describe the method used to investigate force and extension with a spring.
- Secure a clamp to the bench using a G-clamp or a large mass on the base.
- Use bosses to attach two clamps to the clamp stand.
- Attach the spring to the top clamp and a ruler to the bottom clamp.
- Adjust the ruler so that it is vertical and with its zero level with the top of the spring.
- Measure and record the unloaded length of the spring.
- Hang a 100g slotted mass carrier- weight 0.98 N - from the spring. Measure and record the new length of the spring.
- Add a 100g slotted mass to the carrier. Measure and record the new length of the spring.
- Repeat step 7 until you have added a total of 1000 g.
