1. A 56 kg student runs at 5.0 m/s, grabs a hanging rope, and swings out over a lake (Figure directly below). He
releases the rope when his velocity is zero.

a) What is the angle ? when he releases the rope?

b) What is the tension in the rope just before he releases it?

c) What is the maximum tension in the rope?

2. A gun fires a bullet vertically into a 1.40-kg block of wood at rest on a thin horizontal sheet (Figure on the side). If the bullet has a mass of 24.0 g and a speed of 310 m/s, how high will the block rise into the air after the bullet becomes embedded in it?

3. During each heartbeat, approximately 70cm3 of blood is pushed from the heart at an average pressure of 105 mm-Hg. Calculate the power output of the heart, in watts, assuming 70 beats per minute. (6marks)

4. An airplane has a mass of 1.7 x 106 kg, and the air flows past the lower surface of the wings at 95 m/s. if the wings have a surface area of 1200m3, how fast must the air flow over the upper surface of the wing if the plane is to stay in the air?

5. An oxygen atom at a particular site within a DNA molecule can be made to execute simple harmonic motion when illuminated by infrared light. The oxygen atom is bound with a speing-like chemical bond to a phosphorous atom is bound which is rigidly attached to the DNA backbone. The oscillation of the oxygen atom occurs with frequency ƒ=3.7 x 1013 Hz. If the oxygen atom at this site is chemically reoplaced with a sulfur atom, the spring constant of the bond is unchanged (sulfur is just below oxygen in the Period Table). Predict the frequency for a DNA molecule after the sulfur substition.

6. Two wave pulses are travelling in opposite directions with the same speed of 7.0 cm/s as shown in Figure below. At t=0, the leading edges of the two pulses are 15 cm apart. Sketch the wave pulses at t=1.0 s,2.0 and 3.0 s.