JAMB Physics Past Questions & Answers - Page 103

511.

A bullet fired vertically upwards reaches a height of 500m. Neglecting air resistance, calculate the magnitude of the initial velocity of the bullet. [g = 10ms-2]

A.

500.0ms-1

B.

100.0ms-1

C.

70.0ms-1

D.

50.0ms-1

Correct answer is B

V2 = U2 + 2gs

V2 = 0

V2 = 2gs

h = 500m

g = 10ms-2

V2 2 x 10 x 500

V2 = 10,000

V = \(\sqrt{10000}\)

V = 100ms-1

512.

Two strings each inclined at an angle 30o to the horizontal are used to hold a bucket of water weighing 20N. Calculate the tension i n each string

A.

20 (\sqrt{3}\)N

B.

20N

C.

10 (\sqrt{3}\)N

D.

10N

Correct answer is B

No explanation has been provided for this answer.

514.

Which of the following statements describes a body in a stable equilibrium correctly?

A.

a person walking on a tight-rope

B.

ball on a smooth horizontal table

C.

ball resting on an inverted hemisphere bowl

D.

ball in the middle of a nemispherical bowl

Correct answer is D

No explanation has been provided for this answer.

515.

A body is projected with an initial velocity U at an angle O to the horizontal. The time taken by it to reach its maximum height is given by the expression

A.

\(\frac{2u \text{sin}\theta}{g}\)

B.

\(\frac{u^2 \text{sin}^2\theta}{2g}\)

C.

\(\frac{u \text{sin}\theta}{g}\)

D.

\(\frac{u \text{sin}\theta}{2g}\)

Correct answer is C

No explanation has been provided for this answer.