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:
The electrical force between the given charges remains the same.
Explanation:
The expression for the electrical force is as follows as;
Here, k is the constant, are the charges, F is the electrical force and R is the distance between the charges.
It is given in the problem that the magnitudes of the charges and the magnitudes of the separation between the charges are doubled.
Then, the expression of the electrical force becomes as;
Therefore, the electrical force between the given charges remains the same.
Answer:
c. The truck with greater speed
Explanation:
Energy can be defined as the ability (capacity) to do work. The two (2) main types of energy are;
a. Gravitational potential energy (GPE): it is an energy possessed by an object or body due to its position above the earth.
b. Kinetic energy (KE): it is an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents speed or velocity measured in metres per seconds square.
From the above formula, we can deduce that the kinetic energy of an object is directly proportional to the square of the value of its velocity or speed.
Hence, the truck with greater speed would have a greater amount of kinetic energy.
A black sweater. Why? Because black is the most absorbent color while as white is reflecting the light. Hope this helps...