b. in a straight line at constant speed
c. in a circle
d. on an ellipse
e. it can't move if no forces are present
the correct answer was B. However, I am wondering why it cannot be E ? What if an object is in a vacuum at rest or something- it will not move and there are no forces acting on it. I'm confused about this one, can I argue it with teh teacher or am I missing a concept?According to newton's laws, how will an object move if there are no forces acting on it?
The answer is b.
I think the question is referring to Newton's First Law (also known as the Law of Inertia) which states that ';an object at rest tends to stay at rest and that an object in uniform motion tends to stay in uniform motion unless acted upon by a net external force';.
Consider a spacecraft travelling to the Moon. Once it has fired its rocket engines to leave Earth orbit, it will continue on that path and at that same speed without any need for further engine power. So it is moving, but without any force acting on it.
Also, a book sitting on a table is not moving; however, the table is exerting a force upwards equivalent to the mass of the book x gravity. Without this force the book would fall towards the centre of the Earth.
Hope this helpsAccording to newton's laws, how will an object move if there are no forces acting on it?
I think your correct (But that doesn't mean that I am)..
Im sure that if the object is moving, it has a force, kinetic energy.
In physics, a force is whatever that can cause an object with mass to accelerate.[1] Force has both magnitude and direction, making it a vector quantity. According to Newton's second law, an object with constant mass will accelerate in proportion to the net force acting upon it and in inverse proportion to its mass.
Def: The kinetic energy of an object is the extra energy which it possesses due to its motion.
Hope that's of some use.
A
The reason it can't be E is because it was moving in the first place. Forces cause objects to accelerate. At some point in the history of the object, a force must have acted on it to start it moving, but once it has started to move another force must be present to change that motion.
the answer is B. E is just a special case of B where speed = 0. The fact is that if no forces are acting on an object does not mean the object is not moving.
because objects cannot be 100% still, since a moving observer would see it moving.
Gravity is always present. It may be coming from a distant galaxy, but it's there.
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