Waec Physics 2019 Past Questions and Answers

Question 51:

• WAEC 2019

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 52:

• WAEC 2019

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 53:

• WAEC 2019

(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.

Question 54:

• WAEC 2019

State three observable phenomena in which waves behave like a particle.

Question 55:

• WAEC 2019

List three magnetic elements that determine the earth’s magnetic field at a point.