Physics review questions. will give medal to best answer! a pitcher exerts 100.0 n of force on a ball with a velocity of 45 m/s. what is the pitcher's power? a 50.0 kg sailor climbs a 28.3 m rope ladder at an angle of 45 degrees with the mast. how much work did he do? an inclined plane is 5.00 m long and 2.00 m high. what is the ideal mechanical advantage of this machine? a sailboat moves north for a distance of 10.00 km when blown by a wind 30 degrees east of south with a force of 5.00 x 10^4 n. how much work was done by the wind?

1) Using definitions:
Power = Work÷time = (Force×displacement)÷time = Force×velocity
Therefore:
P = F × v = 100.0 × 45.0 = 4500 W

2) The active force is the vertical component of the weight:
F = m · g · sinα = 50 · 9.8 · sin(45) = 346.5N
 
Work is Force times displacement:
W = F · d = 346.5 · 28.3 = 9806J

3) The mechanical advantage of an inclined plane is the ratio between the length and the height of the plane:
MA = l / h = 5 / 2 = 2.5

4) To find the displacement due to the wind, you need to draw the vectors; you will find a triangle rectangle on which you know one angle and the adjacent side and you need to find the hypotenuse. Using trigonometry:
h = a / cosα = 10 / cos(30) = 11.5km = 1.15×10⁴m

You can now find the Work:
W = F · d = 5.00×10⁴ · 1.15×10⁴ = 5.75×10⁸J