On a 10 kg cart (shown below), the cart is brought up to speed with 50N of force for 7m, horizontally. At this point (A), the cart begins to experience an average frictional force of 15N throughout the ride. Find:
a) The total energy at (A)
b) The velocity at (B)
c) The velocity at (C)
d) Can the cart make it to Point (D)? Why or why not?

0.002925 m

Explanation:

Lt = LO(1 +α Δt ) here Lt is total length Lo is original length α is coefficient of linear expansion and Δt is change in temperature

α=25×10^-6

Lt = 5(1+25×10^-6×(70-20))

Lt = 5 (1+25×10^-6×50)

Lt = 5 ( 1+0.00125)

Lt = 5×1.00125

Lt =5.00625 m

α=13.3×10^-6

Lt =5(1+13.3×10^-6×50)

Lt = 5(1+0.000665)

Lt =5.003325 m

hence difference in length =5.00625-5.003325

                                           = 0.002925 m