Give reasons for the following:
a. Knives and swords are supposed to have extremely thin blades.
b. Lorries and trucks carrying heavy loads have 8 tires instead of four, and the
tires are broader.
c. Camels can walk easily in desserts but humans cannot.
d. In a flight, the human ear pain during take-off and landing.
e. A suction cup does not stick on a rough surface.

a. lower surface area, less resistence

b. more surface area, the load is split so no single tire overstrained

c. more surface area, more resistance against the sand. human steps sink down in the sand.

d. rapid change in air pressure on eardrums lead to somewhat-painful tension

e. air would always find its way in so no pressure difference can be achieved

(would indeed appreciate the brainliest if you appreciate the work)

spectral lines lyman is one set

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.