JAMB Physics Past Questions & Answers - Page 278

1,386.

A particle of mass M which is at rest splits up into two. If the mass and velocity of one of the particles are m and v respectively, calculate the velocity of the second particle

A.

\(\frac{mv}{M}\)

B.

\(\frac{Mv}{M - m}\)

C.

\(\frac{mv}{M + m}\)

D.

\(\frac{mv}{M - m}\)

Correct answer is D

(M - m)V2 = mv

V2 = \(\frac{mv}{M - m}\)

1,387.

A car moving with a speed of 90kmh-1 was brought uniformly to rest by the application of the brakes in 10s. How far did the car travel after the brakes were applied?

A.

125m

B.

150m

C.

250m

D.

15km

Correct answer is A

speed = \(\frac{90 \times 10^3}{3600}\) = 25ms-1

Acceleration = velocity change / time = 25 / 10

: Acceleration = 2.5

Using S = Ut + \(\frac{1}{2}\) at^2

S =  \(\frac{1}{2}\) X 2.5 X 10^2 = 125m

1,388.

Which of the following is a fundamental unit?

A.

Newton

B.

Watt

C.

Joule

D.

Second

Correct answer is D

No explanation has been provided for this answer.

1,389.

Which of the following phenomena is called photoelectric effect?

A.

high energy electrons impinge on a metalic anode which then emits photons

B.

a high energy photon emits photons as it slowed down

C.

a metal absorbs quanta of light and then emits electrons

D.

Two electrons are created from a quantum of light

Correct answer is C

No explanation has been provided for this answer.

1,390.

Which of the following are True for \(\alpha\)-decay.

i. mass number, decrease by four.
ii. Atomic number decreases by two.
iii. mass number does not change.

A.

i and ii only

B.

ii and iii only

C.

i and iii only

D.

i, ii, and iii only

Correct answer is A

No explanation has been provided for this answer.