Yh so what did they do here (1 Viewer)

[VictorTango-9W]

for part c btw
isnt the time given in the question the time of flight, and hence cant we just do sx=uxt. like y did the sample answers calculate another value for time. legit confused. if the answers r correct wuts the purpose of the time given in the question.

 

[cossine]

for part c btw
isnt the time given in the question the time of flight, and hence cant we just do sx=uxt. like y did the sample answers calculate another value for time. legit confused. if the answers r correct wuts the purpose of the time given in the question.
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So you are correct. I get the feeling there were some issues with the working out present. The work below uses content from 4 unit math projectile motion. You will see some of the calculations from marker are incorrect. I am bit concern by rounding that was done in the intermediate steps however I am not too knowledgeable about how working out is set in Physics.

So we have
dy^2/d^2t = -g

=> dy/dt = -gt + 11sin(60)
=> y = -gt^2/2 + 11sin(60)*t + 1.2

y = -1.2
=> -gt^2/2 + 11sin(60)*t + 2.4 = 0

dx^2/d^2t = 0

=> x(t) = Ct + C2

=> x(t) = 11cos(60)*t

 

[idkkdi]

for part c btw
isnt the time given in the question the time of flight, and hence cant we just do sx=uxt. like y did the sample answers calculate another value for time. legit confused. if the answers r correct wuts the purpose of the time given in the question.
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the info they gave is wrong. it takes 2.06 s to get to the other side not 3.5s.
iirc this book had quite a few errors.