Answer:

Explanation:
According to the Principle of Energy Conservation and the Work-Energy Theorem, the system is modelled as follows:
, where
.
Then,


Besides, the Principle of Momentum Conservation describes the following model:

The final velocity of the system is:

After substituting in the energy expression:


The mass of the caboose is:




Answer:
Explanation:
Given
radius 
Charge on surface 
Point Charge inside sphere 
Electric Field at 
Treating Surface charge as Point charge and applying Gauss law

where A=surface area up to distance r



Answer:
B.the same as Lily's.
Explanation:
When a disc is rotating on its axis uniformly with some angular velocity , every particle on it rotates with the same angular velocity , because every particle on it completes a rotation simultaneously . So in one rotation they take same time . Hence particles whether on the outer edge or near the axis , all have same angular velocity .
They but differ due to their different linear velocity . Linear velocity of particle near outer edge have greater magnitude. .
Answer: Symbol is I and unit A
Explanation: A represents Amperes
HOPE THIS HELPS!!!!!!!!
Answer: They include elements 57-71, or lanthanides, and 89-103, or actinides. ... Inner transition metals have three incomplete outermost electron shells and are all metals.