Positively charged protons in the nucleus of the gold atom .... rutherford scattering ???
Answer:
D
Explanation:
This will not change the weight and therefore not change the inertia
By the Pythagorean theorem we get
. Thus the resultant velocity will be 5 m/s.
However there is a typo in the choices. It should take 25 seconds to cross the river, not 20 seconds, since the boat actually travels 125 meters due to the water current, and 125/5 = 25 seconds.
Alternatively you can calculate the eastward component of travel and get 100 / 4 = 25 seconds.
The formula for work is

. Plugging in the numbers, you get:


The answer is 30 N.