Question

1. Suppose the vertical height h that Supergirl can jump after she compresses her tendons a distance x1 (beyond her unstretched length) is 25m. How high would she jump after she has compresses her tendons an additional 10% more than before (that is a distance 1.10x1 beyond her unstretched length)?

2. A block of mass 3kg slides along a horizontal table with speed 10m/s. At x = 0 it hits a spring with spring constant 10N/m and begins to experience a friction force. The coefficient of friction is given by 0.5. How far did the spring compress when the block first momentarily comes to rest?

3. From the edge of the rooftop of a building, a boy throws a stone at an angle of 25 degrees above the horizontal. The stone hits the ground 4.20s later,105m away from the base of the building. Ignoring air resistance,

• Find the initial velocity of the stone.

• Find the initial height h from which the stone was thrown.

• find the maximum height H reached by the stone.

• Sketch a graph (x vs. t), (y vs. t), (vx vs. t), (vy vs. t), (ax vs. t) and (ay vs. t) of the

  stone path in the air.

Answer 1