How do you know when to use cosine and sine in physics? Here are two examples:
1)A 70.0 kg sailor climbs an 11.5 m long rope ladder to a mast above at constant velocity. The rope ladder is at an angle of 30.0° with the mast. Assume that the ladder is frictionless. How much work does the sailor do? Here you use cosine
2)A sailor pushes a 50.0 kg barrel at a constant velocity up a 10.0 m long gangplank to the deck of a ship. The sailor applies his force parallel to the dock. The gangplank makes an angle of 30.0° with the dock. How much work? Here you use sine... Why?

Question

How do you know when to use cosine and sine in physics? Here are two examples:
1)A 70.0 kg sailor climbs an 11.5 m long rope ladder to a mast above at constant velocity. The rope ladder is at an angle of 30.0° with the mast. Assume that the ladder is frictionless. How much work does the sailor do?     Here you use cosine
2)A sailor pushes a 50.0 kg barrel at a constant velocity up a 10.0 m long gangplank to the deck of a ship. The sailor applies his force parallel to the dock. The gangplank makes an angle of 30.0° with the dock. How much work?    Here you use sine... Why?

jellybot23 · Answer

@ParthKohli @tkhunny any help?

jellybot23 · Answer

@rvc ??

jellybot23 · Answer

I love physics and I want to understand this

parthkohli · Answer

This is interesting and you'll get used to it soon. Like you'll be able to "see" which one to use. This is how you "see" it.|dw:1454730735756:dw|