1) Multiple-Concept Example 13 presents useful background for this problem. The

Question

1) Multiple-Concept Example 13 presents useful background for this problem. The cheetah is one of the fastest accelerating animals, for it can go from rest to 31.8 m/s in 3.47 s. If its mass is 96.5 kg, determine the average power developed by the cheetah during the acceleration phase of its motion. Express your answer in (a) watts and (b) horsepower.

2) A 64.7-kg skateboarder starts out with a speed of 1.65 m/s. He does 83.4 J of work on himself by pushing with his feet against the ground. In addition, friction does -225 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the skateboarder is 6.86 m/s. (a) Calculate the change (PEf - PE0) in the gravitational potential energy. (b) How much has the vertical height of the skater changed? Give the absolute value.

3)The drawing shows two frictionless inclines that begin at ground level (h = 0 m) and slope upward at the same angle . One track is longer than the other, however. Identical blocks are projected up each track with the same initial speed v0. On the longer track the block slides upward until it reaches a maximum height H above the ground. On the shorter track the block slides upward, flies off the end of the track at a height H1 above the ground, and then follows the familiar parabolic trajectory of projectile motion. At the highest point of this trajectory, the block is a height H2 above the end of the track. The initial total mechanical energy of each block is the same and is all kinetic energy. The initial speed of each block isv0 = 7.43 m/s, and each incline slopes upward at an angle of = 50.0°. The block on the shorter track leaves the track at a height of H1 = 1.25 m above the ground. Find (a) the height H for the block on the longer track and (b) the total height H1 + H2 for the block on the shorter track.

Explanation / Answer

Here ,

initial speed , u = 0 m/s

final speed , v = 31.8 m/s

time , t = 3.47 s

Power produced = total energy /time

Power produced = 0.5 * 96.5 * 31.8^2/3.47

Power produced = 14061 W

the power produced is 14061 Watt

b) as 1 hp = 746 Watt

Power = 14061/746 hp

Power = 18.85 hp

the power produced is 18.85 hp

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.