Why can the formula for gravitational potential energy be written as both GPE=weight X height and as GPE=mgh=fgh

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.

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s

because growing process had stoped after 4-5 year