Abody is projected downward at an angle of 30° with the horizontal from the top of a building 170 m high. its initial speed is 40 m/s. 2.49 (c) at what angle with the horizontal will it strike? (c) 60

The body will strike at angle 60.46°

Explanation:

Vertical motion of body:

 Initial speed, u = 40sin30 = 20m/s

 Acceleration, a = 9.81 m/s²

 Displacement, s = 170 m

 We have equation of motion, v² = u² + 2as

 Substituting

   v² = 20² + 2 x 9.81 x 170

    v = 61.12 m/s

 Final vertical speed = 61.12 m/s

 Final horizontal speed = initial horizontal speed = 40cos30= 34.64m/s

 Final velocity = 34.64 i - 61.12 j m/s

 Magnitude

 Direction

 The body will strike at angle 60.46°

b.

explanation:

10.0

pe = weightxheight = 2000x1000=2,000,000joules