Explanation:
a) Hammer hits a nail
Action: Hammer hitting the nail
Reaction: Nail Hitting the hammer.
B) . Earth's gravity pulls down on a book.
Action: Earth pull downward on the book.
Reaction: The Book pull's the Earth Upward.
C) A helicopter blade pushes air downward.
Action: Blade push air downward
Reaction: The force in pushes the helicopter upward.
Answer:
When acceleration is zero (that is, a = dv/dt = 0), rate of change of velocity is zero. That is, acceleration is zero when the velocity of the object is constant. so probably D
Explanation:
D
Answer:
Image B represents the force on a positively charged particle caused by an approaching magnet.
Explanation:
The most fundamental law of magnetism is that like shafts repulse each other and dissimilar to posts pull in one another; this can without much of a stretch be seen by endeavoring to put like posts of two magnets together. Further attractive impacts additionally exist. On the off chance that a bar magnet is cut into two pieces, the pieces become singular magnets with inverse shafts. Also, pounding, warming or winding of the magnets can demagnetize them, on the grounds that such dealing with separates the direct game plan of the particles. A last law of magnetism alludes to maintenance; a long bar magnet will hold its magnetism longer than a short bar magnet. The domain theory of magnetism expresses that every single enormous magnet involve littler attractive districts, or domains. The attractive character of domains originates from the nearness of significantly littler units, called dipoles. Iotas are masterminded in such a manner in many materials that the attractive direction of one electron counteracts the direction of another; in any case, ferromagnetic substances, for example, iron are unique. The nuclear cosmetics of these substances is with the end goal that littler gatherings of particles unite as one into zones called domains; in these, all the electrons have the equivalent attractive direction.
