1. Use calc to divide. Cannot be whole number.
2. Make a good set of a few hundred eV
3. Deduce the gradient at 3parts
4. Decide to take up as positive. Hence a is negative . After 2s, stone on the way down . Choose negative velocity
5. Find using component method . Vertical component . And horizontal comp separately. Using pythagoaros thm.
6. Centrifugal is new term used in exam. It refers a force opp to centripetal force .
7. Elastic . Use velocity of separation = velocity op approach.
8 Take moment about a point. Not vertical forces and horizontal forces.
9. Has mass and is negatively charged .
10 Upthrust is weight of water displaced. Consider only outer vol of boat. The inner vol is to find weight of oil.the increase in weight due to load = increase in weight of water displaced.
11. Draw 2 forces : W and Fe. If the charge move in dir of W ; decrease in gpe. Move opp to W increase in gpe. So it works for epe the same way. Check if it works for you
12 Drag force= driving force =200 N
Driving force = drag force + weight component .hence new power can be found
13. Drag force =driving force of boat. Power= force x v = kv3. Use power ~v3
14 The resultant force is friction
15 The velocity = rw where T = 24 h
16 F = G 2MM/9x2 = 2/9GMM/x2
17 GMm/r=3.2MJ . Total energy at 2r = 0.5 GMm/2r =1/4GMm/r=3.2 /4 MJ
18 Change the n cycles to radians
19. Graph shows SHM. Hence U shape graph for energy.
20. Two hydrogen atoms in one molecule. Hence twice the number of molecules
21 Suddenly expand imply q=o, expansion means W is negative. U is negative
22 At L1 + x 1/4wavelength. At L2 + x = 3/4 wavelength. Solve for wavelength.
23 The distance bet P and Q read on the x axis is less than a quarter . One quarter of one wavelength is 45 degrees. So less than one quarter is 30 degrees
24 Use young double slit equation . The satellite moving with speed v travel a distance x in a time T = 1/f. So x = v/ f
25 Point 3 arrows to show E due to the charges at the 3corners at the fourth corner.
26 Power = VI .total power = EI , E =( P+p)/I
27 The ratio is the R value. Change in resistance is the difference in the ratio
28 In series resistor is NR. But in parallel is NR/N= R
29 The effective value across voltmeter is 1500 ohm . Voltmeter reading = (12/3500)1500 = 5.14 V
30 UseLHR to determined charge . The current direction and the charge motion is the same , hence positive charge. Smaller radius means decreasing speed
31The two currents are opposite in direction as the flux density at O decrease. Now you can consider point P , if the current in X and Y are in opposite direction it decreases. At Q, the B due to X and Y are in the same direction , so increase.
32.The magnetic flux increase when iron rod enters the solenoid. To oppose the increase in flux the current dip momentarily. When the iron rod leaves , the opp occurs.
33 The magnetic flux is the same but not the magnetic flux density . flux linkage is increased with more turns N.
34The graph is of sine form and period T=2.5ms
35 mean power = 0.5 peak power
36same gradient and lower threshold freq.
40 Use A=0.693(N/half life). Calc (n/half life) and choose the maximum value.
