Work = (force) x (distance)
Each time she lifts the weight, she does
(550 N) x (0.5 m) = 275 joules of work against gravity.
Each time she lets the bar down gently, gravity does
(550 N) x (0.5 m) = 275 joules of work against her muscles.
If the human physical muscular system were 100% efficient, and capable
of absorbing work as well as spending it, then the bodybuilder would do
exactly zero work in the process of 1-up followed by 1-down.
Answer:
b. increasing the number of turns per unit length on the solenoid
e. increasing the current in the solenoid
Explanation:
As we know that energy density depends on the strength of the magnetic field. The magnetic field strength depends on the no of turns of the solenoid and the current passing through it. The greater the number of turns per unit length, greater the current passing through it, more stronger the magnetic field is. As
B = μ₀nI
n = no of turns
I = current through the wire
So the right options are
b. increasing the number of turns per unit length on the solenoid
e. increasing the current in the solenoid
Answer:
Explanation:
For an electric force, F the formula:
F = kQq/r^2
Given:
r2 = 1/2 × r1
F1 × r1 = k
F1 × r1 = F2 × r2
F2 = (F1 × r1^2)/(0.5 × r1)^2
= (F1 × r1^2)/0.25r1^2
= 4 × F1.
