64
A body of mass 25kg, moving at 3ms-1 on a rough horizontal floor is at rest after sliding through a distance of 2.50m on the floor. Calculate the co-efficient of sliding friction. [g = 10.0ms-2]
- A. 0.09
- B. 0.18
- C. 0.36
- D. 0.54
65
The friction which exists between two layers of liquid in relative motion is called
- A. capillarity
- B. surface tension
- C. viscosity
- D. cohension
66
Which of the following statements about a spring balance and/or a chemical balance is not correct?
- A. the chemical balance operates on the principle of moments
- B. the sprin balance operates on Hooke's law
- C. either may be used to measure the weight of a substance
- D. the reading of a spring balance changes over the surface of the earth, while that of the chemical balance remaind constant
67
Each of the following physical quantities is classified as a vector or a scalar quantity. Which of the classifications is correct?
- A. electric potential (Vector)
- B. momentum (scalar)
- C. gravitational field intensity (scalar)
- D. magnetic flux density (vector)
68
Which of the following phenomena is the practical evidence for the existence of the continual motion of molecules?
- A. Translational motion
- B. rotational motion
- C. brownian motion
- D. oscillatory motion