Question 16:

• JAMB 1978

The internationally agreed system of units(SI) for physical measurements are

A. Ib, ft, sec
B. G, m, sec
C. Kg, m, sec
D. Cm, g, sec
E. Kg, cm, sec

Question 17:

• JAMB 1978

To determine the weight of an object you could

A. Use a beam balance
B. Use a spring balance
C. Find the force necessary
D. Use none of these methods
E. Use any of these methods

Question 18:

• JAMB 1978

The force required to make an object of mass m, travelling with velocity v, turn in a circle of radius r is

A. \(\frac{mv^2}{r}\)
B. \(\frac{mr^2}{v}\)
C. \(\frac{mr}{v}\)
D. \(\frac{mv}{r^2}\)
E. \(\frac{mv}{r}\)

Question 19:

• JAMB 1978

The density of a solid is defined as the

A. Mass of the solid compared to the mass of an equal volume of water
B. Amount of water displaced when a unit mass of thesolid is immersed in it
C. Weight per unit volume of the solid
D. Volume per unit mass of the solid
E. Mass per unit volume of the solid

Question 20:

• JAMB 1978

A solid suspended by a piece of string is completely immersed in water. On attempting to lift the solid out of the water, the string breaks when the solid is partly out of the water. This is because

A. The tension in the string decreases as the solid is lifted
B. The mass of the solid has increased
C. The solid apparently weighs less when completely immersed in water than when partially immersed
D. Part of the solid still in water is exerting more force on the string
E. The solid is no longer in equilibrium with water