Kinetic energy possessed by moving train is

.
And mass

.
The formula for kinetic energy is

.
Solve for velocity:


Now put in the data:
Answer:
Number 4 is correct.
Step-by-step explanation:
The first thing I would do is convert that 1.2 kilograms of salt to grams; that would ensure that all the units are the same so we can perform calculations on them.
1.2kg = 1200g
Next, I would find out how many students can do the experiment with 1200g of salt, by finding it how many 25g are in 1200g (by dividing them).

That means we still have 80 students left to provide salt for (128 - 48).
Therefore, he needs an additional 80 amounts of 25g of salt.
Therefore he needs:
Answer:
58240
Step-by-step explanation:
1425 ------ 45600
1820 ------ x
1425*x = 1425x
45600*1820 = 82992000
1425x = 82992000
82992000/1425 = x
58240 = x
Say; Alexander the Great continued exploring, despite his Greek soldiers’ quitting