Answer:
c) curves downward, below the initial velocity vector
Explanation:
A projectile is usually launched from a height, where it is launched with an initial velocity. From that point the gravitational force begins to act on the projectile causing it to decay. As time passes, the projectile advances but its height decreases. So its trajectory is curved downward, below the initial velocity vector.
Answer: NO.
Explanation: Oxygen is not a compound. It has only one element in it.
Answer:

Explanation:
It is given that,
Angular speed of the football spiral, 
Radius of a pro football, r = 8.5 cm = 0.085 m
The velocity is given by :


v = 3.68 m/s
The centripetal acceleration is given by :



So, the centripetal acceleration of the laces on the football is
. Hence, this is the required solution.
As we know by the first law of thermodynamics

here we know that
Q = heat given to the system

W = work done by the system
now here we can say


now we can say that heat will be given as

now here we can say that Jin does the error in his first step while calculation of change in internal energy as he had to subtract it while he added the two energy
So best describe Jin's Error is
<em>B )For step 1, he should have subtracted 78 J from 180 J to find the change in internal energy. </em>
Which element is less reactive, an element whose atoms have seven valence electrons or an element whose atoms have eight valence electrons? Why?<span>an element with 8 valence electrons because it doesn't require any additional electrons to become stable</span>