Question

The force shown in the figure acts on a 1.7-kg object whose initial speed is 0.44 m/s and initial position is x = 0.27 m.

the figure can be found at:
[[webassign dot net forwardslash walker forwardslash 07-16 dot gif]]

(a) Find the speed of the object when it is at the location x = 0.92 m.

(b) At what location would the object's speed be 0.34 m/s?

I have tried several times using W = F_1(x_1) + F_2(x_2-x_1) and then W = KE_f - KE_i to solve for the first part but keep getting the answer wrong. For the second part I have tried many different things but its all just guessing, really. Please Help!!!

Answer 1

find the area of the figure from x1 to x2. That area is the energy in joules added. Then set that area to difference in KE (KEf-KEi)

use basic area under the curves (break it up into rectangles and add).

Answer 2

thanks, I've got the first part correct now. can anybody help out a little more on the second part? I'm still completely confused.

Answer 3

same thing.

figure the change of KE.
Then figure the x to achieve that area.

Answer 4

Thank you.