An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 40 cm. How far past the 40 cm lens does the final image form?.

An athlete is holding 24 lb of weights at a height of 6 inches above the stack as shown. to lower the weights, she applies a constant force of 5 lb to the handle. determine the velocity of the weights immediately before they hit the stack.