The question is incomplete. Here is the complete question.
A floating ice block is pushed through a displacement vector d = (15m)i - (12m)j along a straight embankment by rushing water, which exerts a force vector F = (210N)i - (150N)j on the block. How much work does the force do on the block during displacement?
Answer: W = 4950J
Explanation: <u>Work</u> (W), in physics, is done when a force acts on an object that has a displacement form a place to another:
W = F · d
As the formula shows, Work is a scalar product, i.e, it results in a number, so, Work only has magnitude.
Force and displacement for the ice block are in 2 dimensions, then work will be:
W = (210)i - (150)j · (15)i - (12)j
W = (210*15) + (150*12)
W = 3150 + 1800
W = 4950J
During the displacement, the ice block has a work of 4950J
The Earth takes very nearly (365 and 1/4) days to go around the sun.
If our calendar always had 365 days, then the year would end and re-start
too soon, and the beginning of Spring (and every other season) would
eventually drift into the months after March.
If our calendar always had 366 days, then the year would end and re-start
too late, and the beginning of Spring (and every other season) would
eventually drift into the months before March.
We can't make calendars with an extra quarter-day in each year. But we
keep them lined up with the real year by saving up the quarters, and adding
one full day to the calendar every 4 years.
The Toroid is form when you have wound conductor around circular body. In this case you have magnatic field inside the core but you dont have any poles because circular body dont have ends. This can be used where you want minimum flux leakage and dont need magnatic poles. i.e. toroidal inductor, toroidal transformer.
The Solenoid is forn when you wound conductor around body with limb. In this case magnatic field creates two poles N and S. Solenoids have little bit flux leakage. This used where you want magnatic poles and flux leakage is not an issue. i.e. relay, motors, electromagnates.
1 == toroid
2= solenoid