A child is playing hook-a-duck. The mass of each duck is 50 g. The line has a spring constant of 500 N/m. Calculate the weight of the rubber duck. (Take g = 10 N/kg)
Calculate the extension of the line when a duck is hooked.

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter