Unit 3 Gravitational, Electric, and Magnetic Fields
Lesson 9 Universal Gravitation and Gravitational Fields
29. The earth has a mass of 5.98 x 1024 kg and the moon has a mass of 7.35 x 1022 kg. The distance from the
centre of the moon to the centre of the

55.
a)
From the earths frame of reference, the ball will appear to move in the same direction as the
plane at speed of 300 m/s [forward] 20 m/s [backward] = 280 m/s [forward]. As for the beam
of light, according to the second postulate that Einstein expla

Unit 2 Energy and Momentum
Lesson 5 Work and Energy
17. Energy transformations involved in generating electricity using nuclear power:
The process begins with U-235 decaying into a big pool of coolant, which is potential energy the decaying is kinetic ene

Key questions answers
Lesson 1
1-
Horizontally:
v x =40 cos 50+ 10=35.7 mm /s
Vertically:
v y =40 sin 50=30.6 mm /s
Resultant :
v = 35.7 2+ 30.62=47
=tan 1
2-
mm
s
30.6
=40.6 N of W
35.7
The plane must head in the northwest direction to cancel the effect