Solving for Work of Gravity in Physics: KE, W, PE at UW-Madison

[cyberdx16]

https://mywebspace.wisc.edu/dxiong4/physics%201.bmp?uniq=-w1zg99

for part b i am to find work of gravity, and to do so what i did was

mass*gravity*cos 22*distance(12) to get 436.14, but it seems that it is wrong

i've tried mass*gravity*distance (12)=470.4 and still is not the correct answer, can someone please explain to me what i am doing wrong? thx

 

[cristo]

https://mywebspace.wisc.edu/dxiong4/physics%201.bmp?uniq=-w1zg99

for part b i am to find work of gravity, and to do so what i did was

mass*gravity*cos 22[/color]*distance(12) to get 436.14, but it seems that it is wrong

i've tried mass*gravity*distance (12)=470.4 and still is not the correct answer, can someone please explain to me what i am doing wrong? thx

Check the red part; you want the component of the weight acting parallel to the slope.

 

[HallsofIvy]

Conversely, you want the upward component of displacement-
$sin(\theta)$, not $cos(\theta)$. It's the same as cristo's point.