Recent content by kc0ldeah

Bump? Anyone?

Homework Statement http://imgur.com/BqIoe There is a 50 meter bridge with two supports. The bridge has a mass of 80000kg. A truck of 30000 kg is 15m from one of the supports. What are the forces acting on the ends of the bridge? Answers in back are F_a(support closer to truck): 598000 N...

Bump? Can anyone give some insight?

The equation you gave for T_2 seems to be incorrect. Plugging in .309 for a yields a T_2 of -.725 which is incorrect

Homework Statement http://imgur.com/ZkjXv The given answers are (b) .309 m/s^2 (c) T1= 7.67N, T2=9.22N Homework Equations I_disc = .5(mass_disc)r^2 Sum of Torque = I α a = r α The Attempt at a Solution We will define the system moving right and down as positive to get a positive...

Final Energy = Initial Energy + Work done by friction + Work done by applied force Thank you this is what I really needed to see. I guess the equation my teacher gave me already factored in the fact that friction is an opposing force. That has really been messing me up.

K_f + U_f = K_i + U_i - Force_friction(d) + Work_external If you plug -μ98cos(20°) into that it should be +μ98cos(20°) right? It is -μ98cos(20°) to begin with because Force_friction acts in the opposite direction of the crate's movement. EDIT: But fixing it the way you said gives me 5.65 which...

Sorry that was a typo I will fix it.

Homework Statement A crate of mass 10.0 kg is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 100 N parallel to the incline which makes an angle of 20.0° with the horizontal. The coefficient of kinetic friction is .4 and the cart is pulled 5.00 m. e) What is...

Ah, thanks you two. Ehild's way of explaining seemed to make more sense to me for some reason. So centripetal force is a force observed whenever an object follows a circular path with a constant velocity, but it is a product of other "real" forces that act upon the object, which in this case are...

Thanks for the reply and the welcome. Your explanation of centripetal force as a net force and net result of the normal force and mg helped a lot. I did question where centripetal force came from in certain situations like you mentioned. But I still have some questions. F_net = F_centripetal =...

Homework Statement A speed hump is installed. A 1800 kg car passes over it at 30km/h. The hump follows the arc of a circle with r=20.4 What force does the road exert on the car as the car passes the highest point of the hump? the answer is 1.15x10^4 N according to my professor and this random...