Easy Physics? Huh? Help?
Thanks for visiting guys.. I really need help… i’m having some issues solving the following problems… can someone help me out? I’d like to find out the following…
Can someone describe to me a situation in which a force is applied but no work is done?
(Something i’ve always wondered).. how is work and energy related?
In which on the following is work being done?
A)A person shovels snow off a sidewalk.
B)A worker lifts bricks, one at a time, from the ground to the back of a truck.
C)A roofer’s assistant carries a bundle of shingles across a construction site.
EEEEP!… find the force a person exerts in pulling a wagon 20 m if 1,500 J of work is done.
A car’s engine produces 100kW of power. How much work does the engine do in 5 s? I don’t really understand.
A color TV uses 120 W of power. How much energy does the TV use in 1 hour?
-Thanks In Advance!
Tagged with: Physics Help • Shovels • Sidewalk
Filed under: Physics
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herts epdm rubber roofing
If two forces of the same size but opposite directions press against each other, neither will move. As work = force x distance but the distance is zero, no work is done.
Work and energy are the same thing.
A, B and C
work = force x distance, therefore force = work/distance
The car: energy = work = power x time.
The tv: same equation, energy = power x time, where time = 3600 seconds.
herts flat roof construction
example of force applied but no work done. A person pulling a tree with a rope but the tree dsnt move because der is no displacement. Or else a person carrying a backpack…the force of gravity on the backpack and the displacement in the forward direction give an angle of 90deg. according to the formula W=FcosD…cos 90 wuld give zero…wic bascially gives no work done…there r yr 2 examples…..
Work and Energy are the two sides of the same coin….work is done when energy is transferred…
i think work is done in all the 3 cases…
W=fxd=fW/d=1500J/20m=75N…
use W=P/t convert power 2 watts…and then substitue in the formula…
same as the abv…use the same formulas…power is already given in watts…convert hrs. into seconds…
I hope this helps if any errors lemme knw…
Good Luck!!