1. v y = v 0 sin 25 ° − g t 1 → t 1 = v 0 sin 25 ° / g = 20 ⋅ sin 25 ° / 9.8 = 0.86 ( s ) 1. \ v_y=v_0\sin25°-gt_1\to t_1=v_0\sin25°/g=20\cdot\sin25°/9.8=0.86\ (s) 1. v y = v 0 sin 25° − g t 1 → t 1 = v 0 sin 25°/ g = 20 ⋅ sin 25°/9.8 = 0.86 ( s )
H = 50 + v 0 2 sin 2 25 ° / ( 2 g ) = 50 + 2 0 2 ⋅ sin 2 25 ° / ( 2 ⋅ 9.8 ) = 53.65 ( m ) H=50+v_0^2\sin^225°/(2g)=50+20^2\cdot\sin^225°/(2\cdot9.8)=53.65\ (m) H = 50 + v 0 2 sin 2 25°/ ( 2 g ) = 50 + 2 0 2 ⋅ sin 2 25°/ ( 2 ⋅ 9.8 ) = 53.65 ( m )
H = g t 2 2 / 2 → t 2 = 2 H / g = 2 ⋅ 53.65 / 9.8 = 3.3 ( s ) H=gt_2^2/2\to t_2=\sqrt{2H/g}=\sqrt{2\cdot 53.65/9.8}=3.3\ (s) H = g t 2 2 /2 → t 2 = 2 H / g = 2 ⋅ 53.65/9.8 = 3.3 ( s )
t = t 1 + t 2 = 0.86 + 3.3 ≈ 4.2 ( s ) t=t_1+t_2=0.86+3.3\approx4.2\ (s) t = t 1 + t 2 = 0.86 + 3.3 ≈ 4.2 ( s ) Answer
2. x = v x t = v 0 cos 25 ° ⋅ t = 20 ⋅ cos 25 ° ⋅ 4.2 ≈ 76.1 ( m ) 2.\ x=v_xt=v_0\cos25°\cdot t=20\cdot\cos25°\cdot4.2\approx76.1\ (m) 2. x = v x t = v 0 cos 25° ⋅ t = 20 ⋅ cos 25° ⋅ 4.2 ≈ 76.1 ( m ) Answer
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