Finding the phase shift delta in simple harmonic motion

[myusernameis]

so u = -cos(t) + sqrt(3)sin(t)

so the Wo = 1, and R =2, but how do i find delta?

tan(del) = sqrt(3)/-1, but the answer has it as

u = 2cos(t-2pi/3)

i can't get the 2pi/3 no matter what i do...

thanks

 

[Gregg]

If you follow the posting guidelines I think it will be easier for someone to answer you. The question doesn't seem to be very clear.

 

[myusernameis]

acutally, i found my mistake!

 

[myusernameis]

If you follow the posting guidelines I think it will be easier for someone to answer you. The question doesn't seem to be very clear.

um one more question, what should be the unit for metric?

should i do it in kg, m, seconds, always?

thanks

 

[Gregg]

um one more question, what should be the unit for metric?

should i do it in kg, m, seconds, always?

thanks

yeah always use SI units

 

[myusernameis]

yeah always use SI units

haha

ok, ONE LAST QUESTION (of this thread)..

how do i know when it's "weight" or "mass"? is it in the wordings of the problem?

thanks

 

[Gregg]

haha

ok, ONE LAST QUESTION (of this thread)..

how do i know when it's "weight" or "mass"? is it in the wordings of the problem?

thanks

Weight is a vector, a force. You can see that the dimensions of a force would be kg m/s^2 or Newtons. Mass is a scalar quantity and will be measured, if in SI units, in kg only.

F=MA

Weight = mg

where m is mass and g is the acceleration due to gravity

 

[myusernameis]

Weight is a vector, a force. You can see that the dimensions of a force would be kg m/s^2 or Newtons. Mass is a scalar quantity and will be measured, if in SI units, in kg only.

F=MA

Weight = mg

where m is mass and g is the acceleration due to gravity

thanks!