WAEC Physics Past Questions & Answers - Page 96

476.

The time of flight for a projectile motion is given by the expression

A.

\(\frac{U sin \theta}{g}\)

B.

\(\frac{U sin \theta}{2g}\)

C.

\(\frac{2U sin \theta}{g}\)

D.

\(\frac{U sin 2\theta}{g}\)

Correct answer is C

No explanation has been provided for this answer.

477.

A bird flies at 10ms\(^{-1}\) for 3s, 15ms\(^{-1}\) for 3s and 20 ms\(^{-1}\) for 4s. Calculate the bird's average speed

A.

4.5 ms-1

B.

15.0 ms-1

C.

15.5 ms-1

D.

51.7 ms-1

Correct answer is C

Av. speed = \(\frac{3 \times 15 + 3 \times 10 + 4 \times 20}{3 + 3 + 4}\)

= 15.5 ms\(^{-1}\)

478.

Which of the following substances is the most volatile at room temperature?

A.

water

B.

diesel

C.

petrol

D.

kerosine

Correct answer is C

No explanation has been provided for this answer.

479.

The movement of fluid up or down a narrow tube is

A.

osmosis

B.

brownian motion

C.

capillarity

D.

diffusion

Correct answer is C

No explanation has been provided for this answer.

480.

A metal ball of weight W falls through a column of glycerine of viscosity V. If the ball experiences an upthrust U and terminal velocity is attained, then

A.

W > U + V

B.

W = U + V

C.

W = U - V

D.

W < U + V

Correct answer is B

When terminal velocity is attained, The equation of motion becomes

mg - V - U = 0

\(\therefore\) mg = W = U + V