Question

Figure (3-E8) shows a 11.7 ft wide ditch with the approach roads at an angle of 15° with the horizontal. With what minimum speed should a motorbike be moving on the road so that it safely crosses the ditch ? Assume that the length of the bike is 5 ft, and it leaves the road when the front part runs out of the approach road. Concept of Physics - 1 , HC VERMA , Chapter "Rest and Motion : Kinematics

Answer 1

Solution :

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length of bike=5ft
11.7ft wide ditch

Given horizontal range , x=11.7 +5
x=16.7 ft
θ=15°
acceleration=g=9.8m/s2=32.2ft/s2

Now R=u²Sin2θ/g
u²=Rg/Sin2θ
u²=16.7x32.2/sin30
u²=537.74/(1/2)
u²=1075.48
u=√1075.48
u=32.7 ft/s

∴With 32.7ft/s speed the motor bike should  be moving on the road so that it safely crosses the ditch 

Answer 2

here is your answer mate