Physics Past Questions and Answers

Which of the following devices is used for storing electric charges?

A Transformer
B Ammeter
C Potentiometer
D Capacitor

Question 1937:

An electron of mass 9.1 x 10\(^{-31}\) kg moves with a speed of 2.0 x 10\(^6\) ms\(^{-1}\) round the nucleus of an atom in a Circular path of radius 6.1 x 10(^{11}\) m. Determine the angular speed of the electron.

A 3.28 x 10\(^{16}\) rad s\(^{-1}\)
B 8.55 x 10\(^{3}\) rad s\(^{-1}\)
C 9.11 x 10\(^{13}\) rad s\(^{-1}\)
D 5.22 x 10\(^{15}\) rad s\(^{-1}\)

Question 1938:

An electron of mass 9.1 x 10\(^{-31}\) kg moves with a speed of 2.0 x 10\(^6\) ms\(^{-1}\) round the nucleus of an atom in a Circular path of radius
6.1 x 10\(^{11}\) m. Calculate the centripetal force acting on the electron.

A 7.7 x 10\(^{47}\) N
B 6.0 x 10\(^{-8}\)N
C 3.0 x 10\(^{-14}\)N
D 1.3 x 10\(^{-26}\)N

Question 1939:

A stone of mass 20g is released from a catapult whose rubber is stretched through 5cm. If the force constant of the rubber is 200Nm\(^{-1}\), calculate the speed with which the stone leaves the catapult.

Question 1940:

(a) The diagram above illustrates a projectile motion. Identify each of the physical quantities labeled P, β, H and R.

(b) Write an equation to show the relationship between P, g and Rmax’ where g is the acceleration due to gravity and Rmax is maximum R.