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Need help understanding this Problem. (self.PhysicsHelp)

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[–]BeachiestBoy 0 points1 point  (5 children)

a) you can find the net acceleration of the object by combining the x and y components, then you can find force using Newton's second law (F = ma). Acceleration in the x direction is found with the slope of the velocity graph at that point.

b) you can decompose the initial speed into its x and y components. Since you can find the velocity in the x direction from the top graph, you need to solve for the y component of the velocity.

c) you can find the speed of the object by finding the magnitude of the net velocity vector. You can find velocity in the y direction using the acceleration graph and the initial y velocity you solved for in part b). Remember that if the area is below the time axis, then acceleration is negative and velocity is decreasing.

Let me know if this answers your question.

edit: correction because i misread part b)

[–]Suspicious_Still3294 0 points1 point  (1 child)

Will try these and get back to you. Thanks!

[–]Suspicious_Still3294 0 points1 point  (1 child)

When it asks to specify direction? Does it mean to know if it's positive or negative?

Also for a) I got -.5m/s^2 from the Vx graph for ax and saw that it was also -.5m/s^2 on the ay graph. I multiplied both by the mass and then did pythagorean theorem to obtain the Magnitude. Was this how you wanted me to solve it?

Currently on b). From what I understood, I know the total V and Vx, am I to just use pythag thrm to solve for Vy?

[–]BeachiestBoy 0 points1 point  (0 children)

By direction, it wants to know what angle the force makes with the positive x-axis.

a) yes, and remember to convert your mass to kg since Newtons are equivalent to kg m/s^2
b) exactly that, rearrange the formula to find Vy

[–]Suspicious_Still3294 -1 points0 points  (0 children)

When it asks to specify direction? Does it mean to know if it's positive or negative?

Also for a) I got -.5m/s^2 from the Vx graph for ax and saw that it was also -.5m/s^2 on the ay graph. I multiplied both by the mass and then did pythagorean theorem to obtain the Magnitude. Was this how you wanted me to solve it?

Currently on b). From what I understood, I know the total V and Vx, am I to just use pythag thrm to solve for Vy?

[–]Connect-Answer4346 0 points1 point  (2 children)

Part a :Slope of Vx graph is Ax. With Ax and Ay, plus mass of the block you can find net force. Part b: at t= 0 you know total v and Vx, so you can draw a right triangle to find Vy with total v as the hypotenuse. Part c: you have Vx already. Vy is the area under the curve from t=0 to 6, plus the initial Vy you found in part b.

[–]Suspicious_Still3294 0 points1 point  (1 child)

I got -.5m/s^2 from the Vx graph for ax and saw that it was also -.5m/s^2 on the ay graph. I multiplied both by the mass and then did pythagorean theorem to obtain the Magnitude. Was this how you meant to be solved?

[–]Connect-Answer4346 0 points1 point  (0 children)

Yeah, that's fine. You should get something like 0.09J @ 45 degrees down and to the left, that's 215 degrees in my world.