Correct Question:-
A jack exerts a vertical force of 4.5 × 10³
newtons to raise a car 0.25 meter. How much
work is done by the jack?

Given :-



To find:-


Solution:-
we know :-


So:-



























This is because Newton refined Galileo's idea of inertia and created it as his first law of motion. Galileo stated that it was the propensity of things to resist changes in motion. Newton refined it by including: "Every thing continues in a condition of rest or uniform speed in a straight line except acted on by a nonzero net power".
Answer:
Explanation:
Work is defined as the scalar product of force and distance
W=F•d
Given that
F = 8.5i + -8.5j. +×-=-
F=8.5i-8.5j
d = 2.5i + cj
If the work in the practice is zero, then W=0
therefore,
W=F•ds
0=F•ds
0=(8.5i -8.5j)•(2.5i + cj)
Note that
i.i=j.j=k.k=1
i.j=j.i=k.i=i.k=j.k=k.j=0
So applying this
0=(8.5i -8.5j)•(2.5i + cj)
0= (8.5×2.5i.i + 8.5×ci.j -8.5×2.5j.i-8.5×cj.j)
0=21.25-8.5c
Therefore,
8.5c=21.25
c=21.25/8.5
c=2.5
The force between the two objects is 19.73 nN.
<u>Explanation:
</u>
Any force acting between two objects tends to be directly proportional to the product of their masses and inversely proportional to the square of the distance between the two objects. And this kind of attraction force between two objects is termed as gravitational force.
So if we consider
and
as the masses of both objects and let d be the distance of separation of two objects. Then the force between the two objects can be determined as below:

As gravitational constant
,
= 20 kg and
= 100 kg, while d = 2.6 m, then

Thus, we get finally,

As we know, nano denoted by letter 'n' equals to 
So the force acting between two objects is 19.73 nN.