WAEC Past Questions and Answers - Page 3460

17,297.

A plane inclined at 30o to the horizontal has an efficiency of 50%. Calculate the force parallel to the plane required to push a load of 120N uniformly upon the plane

A.

50.0N

B.

120.0N

C.

200.0N

D.

240N

Correct answer is B

V.R = \(\frac{1}{sin\theta} = \frac{1}{sin 30} = 2\)

M.A = \(\frac{E \times V.R}{100} = \frac{50 \times 2}{100} = 1\)

Effort = \(\frac{load}{M.A} = \frac{120}{1} = 120N\)

17,298.

An apple plant can produce sexually and asexually and it has 40 chromosomes in its leaf cells. How many chromosomes would be in each gamete and somatic cell?

A.

20 chromosomes in the gametes and 10 in the somatic cells

B.

40 chromosomes in the gametes and 20 in the somatic cells

C.

20 chromosomes in the gametes and 40 in the somatic cells

D.

40 chromosomes in the gametes and 40 in the somatic cells

Correct answer is C

No explanation has been provided for this answer.

17,299.

A car of mass 800kg moves from rest on a horizontal track and travels 60m in 20s with uniform acceleration. Assuming there were no frictional forces, calculate the accelerating force

A.

240.0N

B.

800.0N

C.

1600.00N

D.

2400.0N

Correct answer is A

S = at + \(\frac{1}{2} at^2\)

60 = 0 x 20 + \(\frac{1}{2}\) x a x 20

a = \(\frac{3}{10}\)m/s2

F = ma = 800 x \(\frac{3}{10} = 240N\)

17,300.

Which of the following characters is not a morphological variation?

A.

shape of the nose

B.

skin colour

C.

Hair colour

D.

tongue rolling

Correct answer is D

No explanation has been provided for this answer.