1989 - WAEC Physics Past Questions and Answers - page 4
31
Calculate the escape velocity for a rocket fired from the earth's surface at a point where the acceleration due to gravity is 10ms-2 and the radius of the earth is 6 x 106m.
A
7.8 x 106ms-12
B
1.1 x 104ms-1
C
3.5 x 107ms-1
D
6.0 x 107 ms-1
32
The electric force between two point charges each of the magnitude, q at a distance of r apart in air of permittivity is:
A
q2/4πεr
B
rε0/q2
C
4πq/ε0
D
qr2/ε0
correct option: e
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