Wow, I'm wondering this too - how the book got 1.15.
Tom, or anyone else willing to help:
M(girl)V(girl)[initial] + M(plank)V(plank)[initial] = M(girl)V(girl)[final] + M(plank)V(plank)[final]
So: 0 + 0 = (45)(1.50) + (150)(V)
So: 0 = 67.5 + 150(V)
So: 67.5 = -150(V)
So: V =...
tyco. lol. For some reason I knew you'd say that just to try and prove a point. OK. you win, the cart might have to be moving 0.1 m/s or more... Or maybe it's a typhoon and the raindrops are shooting through your "cart". But then it wouldn't matter because the wind would pick up and since you...
If you're solely given the Force of an object over Time... I don't see how you could find the mass of the object unless you were somehow able to calculate the acceleration.
If the object was traveling around a circular path, and you were given the velocity or able to calculate the velocity...
Terp -- What class are you in and when? You might be in my class.
Tyco -- You're wrong. If the rain was coming down at an angle, it still has LESS horizontal velocity than the cart, so the cart will have to give it more horizontal velocity, or, the cart will still exert a hnorizontal force...
Hey, Terp!
Do you go to the university of maryland? If you do, so do I, let me know.
Anyways, to answer your question...
So, the object is moving at a constant speed. It needs to force to keep it moving it just keeps going on this frictionless surface. Well, the raindrops are falling...