Answer:
Explanation:
The acceleration of gravity is 9.8m/s^2.
So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.
(You can ignore the fact "at" is -30 instead 30, it's because the directions two velocity travel are opposite. )
We can now know the time it takes to make the ball stop just by the gravitational force is about 3 sec.
Use another formula S=1/2at^2, to find out the S(height) is 1/2*9.8*3^2=44.1, which is approximately D.45m .
The scientist that described an atom made a solid positively charged substance with electrons dispersed throughout it was: Ernest Rutherford
In 1911 Ernest Rutherford proposed his atomic model in which he considered the atom as a positively, densely charged center called a nucleus in which the electrons circulate around the core with a negative charge.
<h3>What is an atom?</h3>
The atom is the smallest part of the composition of matter, it is indivisible and is composed of a nucleus that has protons and neutrons, and around the nucleus there are the electrons.
Learn more about the atom at: brainly.com/question/17545314
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Answer:
2250N
Explanation:
W= mg,
where W= weight
m= mass
g= acceleration due to gravity
Given that the body is 90kg, m= 90kg.
Acceleration due to gravity of planet
= 2.5(10)
= 25 m/s²
Weight of body on planet
= 90(25)
= 2250N
*Mass is the amount of matter an object has and is constant (same on earth and the planet).
Answer:
18.4 m
Explanation:
(a)
The known variables in this problem are:
u = 1.40 m/s is the initial vertical velocity (we take downward direction as positive direction)
t = 1.8 s is the duration of the fall
a = g = 9.8 m/s^2 is the acceleration due to gravity
(b)
The vertical distance covered by the life preserver is given by

If we substitute all the values listed in part (a), we find
