He produced the first orderly arrangement of known elements, he used patterns to predict undiscovered elements
Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Answer:False.
Explanation: HIV is a viruse that only shows symptoms after a few weeks. in Fact HIV does not show any physical symptoms. So, no you can not tell if someone has or is been infected by HIV by directly looking at them.
Have a Nice Day!!! =)
Answer:
Explanation:
The application of Gauss's law is used in the derivation as shown with detailed step by step in the attached file.
The potential difference on this spherical capacitor is ΔV = Va - Vb = kQ/a - kQ/b = kQ(1/a - 1/b)
Answer:
200 m\ s Ans .....
Explanation:
Data:
f = 200 Hz
w = 1.0 m
v = ?
Formula:
v = f w
Solution:
v = ( 200)(1.0)
v = 200 m\s <em>A</em><em>n</em><em>s</em><em> </em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em>