Question 4471:

• NECO 2003

The mode of transference of heat which does not require any material medium is ____________

A. Conduction
B. Convection
C. Evaporation
D. Radiation
E. Transmission

Question 4472:

• NECO 2003

The area under the curve of a velocity time graph represents ____________

A. Acceleration
B. Distance covered
C. Instantaneous speed
D. Time taken
E. Work done

Question 4473:

• NECO 2003

A body is launched from the earth’s surface, of radius R, so that it just escapes from the gravitational influence of the earth; If the gravitational constant is G and the mass of the earth is M, what is the escape velocity of the boby.

A. \(\sqrt{2GM}\) ÷ R
B. \(\frac{\sqrt{2GM}}{R}\)
C. \(\frac{\sqrt{2G}}{MR}\)
D. \(\sqrt{2GMR}\)
E. \(\frac{\sqrt{R}}{2GM}\)

Question 4474:

• NECO 2003

A ball of mass m moving at velocity u collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.

A. \(\frac{u}{v}\)
B. \(\frac{mu}{2}\)
C. U
D. 2u
E. \(\frac{u}{m}\)

Question 4475:

• NECO 2003

Which of the following statement(s) is/are correct?

I. When a liquid expands its density falls
II. When a mercury-in-glass thermometer is placed in a hot liquid, the mercury level first descends and then rises.
III. The apparent expansion of a liquid is greater than its real expansion.

A. I only
B. II only
C. III only
D. I and II only
E. II and III only