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## Homework Statement

Only (b) part[/B]

## Homework Equations

time of flight= (2⋅u⋅sinθ)/g ---------------- - 1

total distance (range)= u⋅cosθ * time of flight (s=vt)

=u⋅cosθ * (2⋅u⋅sinθ)/g --------------- -2

=u

^{2}⋅2sinθcosθ/g

= u

^{2}⋅sin2θ/g ---------------- -3

## The Attempt at a Solution

[/B]

Rather than using equation 3, I decided to use 2, as 3 is just 2 simplified.

Distance= u⋅cosθ * (2⋅u⋅sinθ)/g

= (60*cos30°)*(2*60*sin30°)/10

= (60*(√3/2))*(2*60*(1/2))/10

=(30*60√3)/10

=180√3 metres

However by equation 3,

Distance= u

^{2}⋅sin2θ/g

= 3600*(sin30°)

^{2}/10

= [3600*(1/4)]/10

= 900/10= 90 metres.

Where is the error please tell me!

THank you for reading.

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