JAMB Physics Past Questions & Answers - Page 239

1,191.

A force of 100N stretches an elastic string to a total length of 20cm. If an additional force of 100N stretches the string 5cm further, Find the natural length of the string

A.

15cm

B.

12cm

C.

10cm

D.

8cm

E.

5cm

Correct answer is A

Using, f1 = f2

e1 = 20 - L ; e2 = 5cm

\(\frac{f_1}{e_1}\) = \(\frac{f_2}{e_2}\)

\(\frac{100}{20 - L}\) = \(\frac{100}{5}\)

hence, L = 15cm

1,193.

Two masses 40g and 60g respectively, are attached firmly to the ends of the light meter rule. The center of gravity of the system is

A.

at the mid-point of the meter rule

B.

40cm from the lighter mass

C.

40cm from the heavier mass

D.

60cm from the heavier mass

E.

indeterninate because the meter-rule is light

Correct answer is C

No explanation has been provided for this answer.

1,194.

Which of the following is NOT a force?

A.

Friction

B.

Tension

C.

Upthrust

D.

Weight

E.

Impulse

Correct answer is E

No explanation has been provided for this answer.