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A projectivle is fired form the top of a 40 m hnigh cliff with an initial speed of 50 m/s at an unknown angle. Find its speed when it hits the ground. |
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Answer» `h=40m, u=50m/sec` let the speed be v when it strikes the ground. Applying law of conservation of energy, `mgh+1/2mu^2=1/2mv^2` `rarr 10xx40+(1/2)xx2500=1/2v^2` `rarr v^2=3300` `rarr v=57.4m/sec=58m/sec` |
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