According to the Law of Conservation of Energy, energy is neither created nor destroyed. It is only transferred through different forms of energy. For the following situations, the conversion of energy is as follows:
*Turning on a space heater = electrical energy⇒heat energy
*Dropping an apple core into the garbage = potential energy⇒kinetic energy
*Climbing up a rope ladder = kinetic energy⇒potential energy
*Starting a car = chemical energy⇒mechanical energy
<span>*Turning on a flashlight = chemical energy</span>⇒electrical energy
The gravitational force between <em>m₁</em> and <em>m₂</em> has magnitude
while the gravitational force between <em>m₁</em> and <em>m₃</em> has magnitude
where <em>x</em> is measured in m.
The mass <em>m₁</em> is attracted to <em>m₂</em> in one direction, and attracted to <em>m₃</em> in the opposite direction such that <em>m₁</em> in equilibrium. So by Newton's second law, we have
Solve for <em>x</em> :
The solution with the negative square root is negative, so we throw it out. The other is the one we want,
Answer:
B) 100 J
Explanation:
Assuming the distance given is measured along the incline, the vertical change in height is (5 m)(sin 30°) = 2.5 m. Then the change in potential energy is ...
∆PE = mg(∆h) = (4 kg)(10 m/s^2)(2.5 m) = 100 J
Despite current has a magnitude and a direction, like vectors, it is a scalar because it doesn't obey laws of vector addition. For instance, if we consider a junction of
in a circuit, and two currents entering this junction, we know that the resultant current is just the algebraic sum of the two currents, not the vector sum, so it is not a vector quantity.