Answer:
(e) 98,1 KJ
Explanation:
The engine produces 19%; it means, it rejects 81% of energy. ⇒ 81/19=4.26 times.
The engine produces 23 kJ; it means it rejects 23 * 4.26 = 98.05263 kJ
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.
Answer:
Sarah is right
Explanation:
This is an exercise that differentiates between scalars and vectors.
A scalar is a number, instead a vector is a number that represents the module in addition to direction and sense.
In this case, the distance (scalar) traveled is a number, which is why it is worth 1500m, but the displacement is a vector and since the point where it leaves is the same point where the vector's modulus arrives is zero, so the DISPLACEMENT VECTOR is zero
consequently Sarah is right