.

.

(1bi)
(i)Firstly, the net force acting upon the object must be zero.
(ii)Secondly, the net torque acting upon the object must also be zero.

(1bi)
(i)the net force acting upon the object must be zero.
(ii)Secondly, the net torque acting upon the object must also be zero.

1bii.
Let F1 = 4N and F2 = 3N.
Resultant force (R) = √(F1^2 + F2^2)
= √((4N)^2 + (3N)^2)
= √(16N^2 + 9N^2)
= √(25N^2)
= 5N

(1axi)

*(Pick 2)*

(i)I avoid parallax error by placing my eyes vertically on the meter rule when taking my readings.
(ii)I avoid drought.
(iii)I avoid Zero error by making necessary adjustment to the meter rule before starting my practicals.

(2bi)
If the angle of incidence (θ₁) is greater than the critical angle (θ_c), then total internal reflection occurs.

(2bii) Snell’s law states that the ratio of the sine of the angle of incidence (θ₁) to the sine of the angle of refraction (θ₂) is equal to the ratio of the velocities of light in the two media, which is also equal to the inverse ratio of their refractive indices.

NUMBER 3