Yes that's a true statement. That's why grandmother put a hot water bottle to warm up her bed, and not a hot bar of steel or lead.
Answer:
a) Explanation below. b) Explanation below
Explanation:
Torque is defined as the product of a force by a radius, while momentum is defined as the product of force by a distance. Mathematically we would have
T = F * r
M = F * d
where:
T = torque = [N*m]
M = moment = [N*m]
F = force =[N]
d = distance [m]
r = radius [m]
Although they have the same units, the difference between them is the application. For the case of torque this is always applied in parts that are in rotation, such as the shafts of cars, the shafts of pumps, torque in gears and etc. While the moment can be applied to a body without the need for it to rotate.
A couple, is as its name suggests a couple of forces of equal magnitude but opposite sense and do not share a line of action. A body under the action of a couple of forces tends to rotate the body without moving it from one point to another.
Answer:
because it gives a complete thought
<span>If an inductor is connected across an ac source and suppose the frequency of the source is doubled, then t</span>he inductive reactance of the inductor is also doubled. The inductive reactance (XL) is the t<span>he opposition to current flowing through a coil in an AC circuit, the </span>impedance measured in Ohms and can be calculated with the following formula:
XL=2*pi*f*L,
where f is the frequency. So, if the frequency is doubled than also the inductive reactance is doubled.
A positive way that Friction helps in your every day life would be when you drive to work or school. There is friction acting upon your tires, without it you would continue to constantly move forwards until you have struck something, bringing you to a halt. Therefore friction is a positive in this case, however friction can also be a negative in your everyday life. This is possible because friction can be used against you, say you were dragging a box from point A to point B up a hill. You must use mechanical energy however going uphill already presents a problem, now if the wind were to blow you would be moving against friction, this is a negative.
