Explanation:
It is given that,
= -40 mi/h,
= -40 mi/h
The negative sign indicates that x and y are decreasing.
We have to find
. Equation for the given variables according to the Pythagoras theorem is as follows.

Now, we will differentiate each side w.r.t 't' as follows.

or, 
So, when x = 4 mi, and y = 3 mi then z = 5 mi.
As, 
= 
= 
= 52
Thus, we can conclude that the cars are approaching at a rate of 52 mi/h.
The most likely element is silver
in second place is copper
Answer:
Frequency = 3.0 Hertz
Explanation:
Given the following data;
Period = 0.333 seconds
To find the frequency;
Mathematically, frequency of a wave is given by the formula;
Frequency = 1/period
Substituting into the formula, we have;
Frequency = 1/0.333
Frequency = 3.0 Hertz
Given that,
Mass of the stone, m = 400 g = 0.4 kg
Initial speed, u = 20 m/s
It is climbed to a height of 12 m.
To find,
The work done by the resistance force.
Solution,
Let v is the final speed. It can be calculated by using the conservation of energy.

Work done is equal to the change in kinetic energy. It can be given as follows :

So, the required work done is 32.99 J.
Answer:
Electrons and protons are connected with one another in term of charge and size.
Explanation:
- The size of electron and proton is always same in any atom but they possess opposite charge.
- Electron in any atom carries negative charge where as proton carries the positive charge.
- In any neutral atom the charge between electron and proton is balanced along with the size.
- The nucleus of any atom bounds only proton and neutron but the electron is present revolving around the nucleus.