Respuesta :
The speed of the block at point B = 6.36 m/s
Given data :
Mass ( m ) = 10 kg
Angle of inclination ( θ ) = 30°
Length of incline = 5 m
Determine the speed of the block at a point B on the incline
First step : Calculate the work done by frictional force
given that there is no friction on the horizontal plane. Vinclined = Vhorizontal
∴ Work done by frictional force ( Wf ) = F * L cos 180
= - ( μ_k * N ) L
= - (0.1 * 84.86 ) * 5 = - 42.4 Joule
where N = mg cos 30°
= 10 * 9.8 * 0.866 = 84.86
Next step : Calculate the speed of the block at point B
applying work energy theorem
Wf = ΔK.E + ΔP.E
= ( 1/2 mv² - 0 ) + ( 0 - mgh )
∴ - 42.48 = 1/2 mv² - mgh
1/2 mv² = mgh - 42.48
= 10 * 9.8 * 5 sin 30° - 42.4
v² = 40.52
V ( speed of the block at point B ) = 6.36 m/s
Hence we can conclude that the speed of the block at point B = 6.36 m/s
Learn more about speed on frictionless surface : https://brainly.com/question/9968388
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