Consider a rock that is thrown off a bridge of height 26 m at an angle = 25° wit

Question

Consider a rock that is thrown off a bridge of height 26 m at an angle = 25° with respect to the horizontal as shown in thefigure above. If the initial speed the rock is thrown is11 m/s, find the following quantities: (a) The time it takes the rock to reach itsmaximum height.
.47 s

(b) The maximum height reached by the rock.
27 m

(c) The time at which the rock lands.
2.8 s

(d) The place where the rock lands.
28 m/s

(e) The velocity of the rock (magnitude and direction) just beforeit lands.
I got a-d but I'm having trouble finding themagnitude and direction and they are looking for one answer to bem/s and the other to be degrees. I thought I got themagnitude many times but apparently my answer is still wrong. I got -22.8 m/s and I do not know how to find the direction. Any help is appreciated! (a) The time it takes the rock to reach itsmaximum height.
.47 s

(b) The maximum height reached by the rock.
27 m

(c) The time at which the rock lands.
2.8 s

(d) The place where the rock lands.
28 m/s

(e) The velocity of the rock (magnitude and direction) just beforeit lands.
I got a-d but I'm having trouble finding themagnitude and direction and they are looking for one answer to bem/s and the other to be degrees. I thought I got themagnitude many times but apparently my answer is still wrong. I got -22.8 m/s and I do not know how to find the direction. Any help is appreciated!

Explanation / Answer

horizontal velocity remains constant sine horizontalacceleration=0 horizontal velocity=11*cos25=9.97 h=26+max height=26+27=53 let vertical velocity before it hit the ground=v v2=u2+2*g*h v2=0+2*9.8*53 v=32.23 m/s resultantvelocity=(9.972+32.232)=33.74 m/s direction=tan-1(32.23/9.97)=72.81 degree belowhorizontal

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