Answer:
a) t = 0.74s
b) D = 4.76m
c) Vf = 5.35m/s
Explanation:
The ball starts rolling when Vf = ωf*R.
We know that:
Vf = Vo - a*t
ωf = ωo + α*t
With a sum of forces on the ball:




With a sum of torque on the ball:



Replacing both accelerations:


t=0.74s
The distance will be:


Final velocity:

Vf=5.35m/s
Answer:
A. chemical substance whose atoms all have the same number of protons
Explanation:
An element is a substance which contains identical atoms that have the same number of protons in the nucleus.
Elements are arranged in the periodic table according to their atomic number (= number of protons): so atoms of different elements have a different number of protons in their nuclei.
For a neutral atom, the number of electrons around the nucleus is also equal to the number of protons.
Moreover, atoms of the same element can have a different number of neutrons, despite having the same number of protons - these atoms are called isotopes.
3.33 seconds.
<u>Explanation:</u>
We can find the speed of the body using the formula,
Speed = Distance traveled in meters / time taken in seconds
= 450 m / 30 seconds
= 15 m/s
So per second the distance traveled by the body is 15 m.
So time needed to travel 50 m can be found as,
time = distance/speed
= 50 m / 15 m /s
= 3.33 s
To solve the problem we will simply perform equivalence between both expressions. We will proceed to place your units and develop your internal operations in case there is any. From there we will compare and look at its consistency


At the same time we have that



Therefore there is not have same units and both are not consistent and the correct answer is B.
Material medium electric waves