Question

A fisherman casts his lure at an angle of 33 degrees above the horizontal. The lure reaches a maximum height of 2.3 m. Assuming no frictional forces, what was the initial velocity the fisherman gave the lure when he cast it?

Answer 1

Answer:

12.32 m/s

Explanation:

Using the formula of maximum height of a projectile,

H = u²sin²Ф/2g................... Equation 1

Where H = maximum height, u = initial velocity, Ф = angle of projection, g = acceleration due to gravity

make u the subject of the equation

u = √(2Hg/sin²Ф)............ Equation 2

Given: H = 2.3 m, Ф = 33°, g = 9.8 m/s²

Substitute into equation 2

u = √[(2×2.3×9.8)/sin²33°]

u =√ [45.08/(0.545)²]

u = 45.08/0.297

u = √(151.785)

u = 12.32 m/s