Becomes a +1 ion for this
Answer:
The unbalanced force that caused the ball to stop was friction
Explanation:
As Newton's second law states, the acceleration of an object is proportional to the net force applied on the object:
therefore, in order to move at constant speed, an object should have a net force of zero (balanced forces) acting on it.
In this case, the ball slows down and eventually comes to a stop: it means that the ball is decelerating, so there are unbalanced forces (net force different from zero) acting on it. The unbalanced force acting on the ball is the friction: friction is a force against the motion of the object, which is due to the contact between the surface of the ball and the surface of the street, and this force is responsible for slowing down the ball.
Answer:
Explanation:
a ) Between r = 0 and r = r₁
Electric field will be zero . It is so because no charge lies in between r = 0 and r = r₁ .
b ) From r = r₁ to r = r₂
At distance r , charge contained in the sphere of radius r
volume charge density x 4/3 π r³
q = Q x r³ / R³
Applying Gauss's law
4πr² E = q / ε₀
4πr² E = Q x r³ / ε₀R³
E= Q x r / (4πε₀R³)
E ∝ r .
c )
Outside of r = r₂
charge contained in the sphere of radius r = Q
Applying Gauss's law
4πr² E = q / ε₀
4πr² E = Q / ε₀
E = Q / 4πε₀r²
E ∝ 1 / r² .
Answer:
Feathers are great thermal insulators.
Explanation:
Feathers are great thermal insulators. The loose structure of down feathers traps air.
As a result, energy cannot be transmitted easily through down feathers. This means birds are insulated from cold air outside, plus their body heat doesn't escape easily either.
Human beings discovered that down feathers are good for insulation long ago. For example, documents from the 1600s show that Russian merchants sold “bird down" to the Dutch hundreds of years ago.
Today, down is used in all sorts of products, including coats, bedding, and sleeping bags, to help better insulate the user from cold weather. Down can be collected from many different types of birds, but most of today's supply comes from domestic geese.
If you have a down coat or comforter, is it all down? In the United States, laws require that products labeled “100 percent down" contain only down feathers.
If your product is labeled “down," it can contain a mixture of both down feathers and synthetic fibers. Not all down feathers are created equal, though.
Down insulation is rated on a measure called “fill power." The higher the fill power, the more the down insulates.
The highest fill-power rating — 1200 — goes to eiderdown, which comes from the Common Eider duck. Eiderdown tends to be expensive.
