Answer:
Force on superball will be 
Explanation:
We have given mass of superball m = 52 gram = 0.052 kg
Velocity change from 20 m/sec downward to 14 m/sec upward
Let downward velocity is positive then upward velocity is negative
So downward velocity is + 20 m/sec and upward velocity is -14 m/sec
Time is given as 1800 sec
We know that acceleration is rate of change of velocity
So 
According to newton second law
Force = ma = 0.052×0.0188 
Answer:
The potential energy of the rock = 10.5 kN
Explanation:
Mass of rock = 25 kg
Acceleration due to gravity = 10 m/s²
Height = 42 m
Potential energy, PE = mgh, where m is the mass, g is acceleration due to gravity and h is the height.
PE = 25 x 10 x 42 = 10500 N = 10.5 kN
The potential energy of the rock = 10.5 kN
The correct answer would be the letter B.) NaF this attracts opposite charges. The final formula of sodium fluoride would be NaF it’s <span>compound is formed by the complete transfer of electrons from a metal to a nonmetal.</span>
Answer:
I. don't. get. this. question
C. Demand increases
Pace increases
The answer should be C. Both matter and energy because physical sciences are sciences concerned with the study of inanimate natural objects, including physics, chemistry, astronomy, and related subjects.
Matter and energy fall in with chemistry