High school???
No way
It's work.
Answer:
After 4 s of passing through the intersection, the train travels with 57.6 m/s
Solution:
As per the question:
Suppose the distance to the south of the crossing watching the east bound train be x = 70 m
Also, the east bound travels as a function of time and can be given as:
y(t) = 60t
Now,
To calculate the speed, z(t) of the train as it passes through the intersection:
Since, the road cross at right angles, thus by Pythagoras theorem:


Now, differentiate the above eqn w.r.t 't':


For t = 4 s:

Answer:
Some elements are reactive because the outermost energy levels of their atoms are only partially filled. Therefore, these atoms can easily gain or lose electrons to form ions. The atoms of nonreactive elements have filled outermost energy levels
Explanation:
hope this answers your ?
Answer:
Hipparchus was an ancient Greek who classified stars based on the brightness in 129 B.C. He grouped the brightest stars and ranked them 1 (first magnitude) and dimmest stars as 6 (sixth magnitude). Thus, the smaller numbers indicated brighter stars. Now, the scale extends in negative axis as well. More the negative number, brighter is the star. For example, Sun has magnitude -26.74.
This the apparent magnitude which means the classification is based on the brightness of the star as it appears from the Earth.
Answer:
-0.79 J
Explanation:
We are given that





We have to find the work done by the electric force on the moving point charge.


Work done,
Where 
Using the formula

