64
A particle of mass 2.5 x 10-6kg revolving around the earth has a radial acceleration of 4 X 107 ms-2. What is the centripetal force of the particles?
- A. 6.25 x 10-14N
- B. 1.60 x10-13N
- C. 5.00 x 10N
- D. 1.00x102N
- E. 2.00x1O2N
65
Which of the following instruments is suitable for making the most accurate measurement of the internal diameter of a test tube?
- A. metre rule
- B. A pair of callipers
- C. A micrometer screw gauge
- D. A tape rule
- E. A set square