2013 HSC COURSE
HSC biology, physics, economics, english & four unit mathematics
HSC biology, physics, economics, english & four unit mathematics
417
0.0 (0)
Nicht sichtbar
Nicht sichtbar
Kartei Details
Karten | 417 |
---|---|
Sprache | English |
Kategorie | Allgemeinbildung |
Stufe | Mittelschule |
Erstellt / Aktualisiert | 10.04.2013 / 05.04.2019 |
Lizenzierung | Kein Urheberrechtsschutz (CC0) |
Weblink |
https://card2brain.ch/box/2013_hsc_course
|
Einbinden |
<iframe src="https://card2brain.ch/box/2013_hsc_course/embed" width="780" height="150" scrolling="no" frameborder="0"></iframe>
|
Weight:
- Weight = the force on an object due to gravity
- Weight(N) = Mass(Kg) x Gravity(ms-2)
- Vector quantity
- measured in Newtons (N)
Relationship between gravitational potential energy and work done.
- Gravitational Potential Energy of an object in a gravitational field is the work done in moving an object from an infinite distance to that point
- Work = Fd = mgd = mgh
Practical: Acceleration due to gravity using a pendulum
- Aim: to calculate the acceration due to gravity using a pendulum
- Hypothesis: The calculation will be a ≈ 9.8ms-2
- Risk: the weighted retort stand may be top heavy, causing it to fall off the desk and cause significant damage to those nearby. Therefore weight the retort stand down using a battery pack.
- Materials: 1x retort stand, 1x protractor, 1x battery pack, 1x metal ball, 1x length of string, 1x scissors, 1x ruler, 1x mass balance, 1x stopwatch
- Method: 1. measure the mass of the metal ball, m. 2. set up the simple pendulum with string length 1.2m. 3. measure an angle of 20° then release, timing t for 5 swings 4. repeat step 2 and 3 two more times keeping the angle and mass constant. 5. calculate average time and then period, T (time for one swing). 6. repeat steps 2-5 for Length, L, of range 0.2 to 1.2m 7. Graph T2 against L and use the gradient o determine the acceleration due to gravity.
- Graph of T2 against L will result in a straight diagonal line. comment: accurate as T2 is directly proportional to L (from equation T2 = (4π2L)/g)
- Results: Using values of T2 and equation T2 = (4π2L)/g) calculate a value for g.
- Discussion: repetitions ensured reliability however a number of errors including the string's mass and air resistance not being taken into account. timing errors from reaction time and measurement errors associated with measuring the 20° angle.
- Conclusion: Length was the variable effecting T. Equation varified at T recorded ≈ T estimated from equation. Acceleration measured to be 9.78 ms-2
universal gravitational constant
G = 6.67 x 10-7 N(m/kg)2
Newton's second law
- Force (F) = Mass (m) x Gravity (a)
- vector quantity
- measured in Newtons (N)
Gravitational Potential Energy
- GPE of an object at a point in a gravitational field = work done in moving the object from a infinite distance to that point.
- Ep = -(Gm1m2)/r
- Ep is highest at infinity when the object escapes the gravitational field (0J) and lowest at the surface of the object providing the field (negative)
- When an object is lifted against a gravitational field work is done and Ep increases
- As an object moves towards the source of the field Ep ⇒ Ek
Ep = 0J
- When object is no longer in a gravitational field
Ep is highest
- at infinity (0J)