I have to submit my homework soon and I am not familiar with these concepts. can anybody do then for me?
1 answer:
#4). The concepts are: A). acceleration is always in the direction of the force, and B). friction always acts in the direction opposite to motion. (that's B)
#5). The concepts are: A). the NET force is the sum of all the individual forces acting (on this car, it's 1600N forward). and B). Force = (mass) x (acceleration). So Acceleration = (force) / (mass). For this car, that's (1600N forward) / (800 kg) .
#6). The concept is: As long as you don't exceed the "proportionality limit" of a spring, its extension is proportional to the load on it. That means that the change in extension is always proportional to the change in the load. So now, look at the table: As long as the load is 10N or less, the spring stretched 3cm longer for every 2N more of load. But if the load is somewhere between 10N and 12N, that relationship disappears. Something changes between 10N and 12N of load. The spring's "elastic limit" is somewhere in that slot.
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1. C. Gravitational attraction exists between the two objects.
Explanation:
Gravitational attraction is always exerted between two objects which have mass, and its magnitude is given by:
where G is the gravitational constant, m1 and m2 the masses of the two objects, and r the separation between them. Since the two objects have for sure non-zero masses m1 and m2, even if they are 20 miles apart, the value of the gravitational attraction F is non-zero, so the correct answer is C.
2. D. Two atoms come together to form a molecule.
Explanation:
this outcome is actually caused by the electrostatic forces between the two atoms, not by gravitational force. In fact, gravitational force becomes relevant only when the masses of the two objects involved are large enough: this is the case for planets, stars, galaxies, and objects in the universe. However, two atoms have very small masses, so the gravitational force between them is really negligible. On this smaller scales, the electrostatic force is much stronger than the gravitational force, so the electrostatic force is the real responsible for the formation of bonds between atoms.