A motorcyclist moving along a horizontal section of the road saw that a man standing by the road hit the rail
A motorcyclist moving along a horizontal section of the road saw that a man standing by the road hit the rail, and after 2 seconds he heard a sound. Determine the speed of the motorcyclist if he drove past the person 36 seconds after the impact.
t = 2 s.
T = 36 s.
Vsv = 340 m / s.
Vm -?
From hitting the rail until the moment the motorcyclist heard the sound, he traveled the distance S1 = Vm * t.
The sound from the moment of hitting the rail and meeting the motorcyclist traveled the distance S2 = Vsv * t, where Vsv is the speed of sound, which we will consider Vsv = 340 m / s.
The distance S that the motorcyclist traveled from the moment of impact to the place of impact can be expressed by the formula: S = Vm * T.
S = S1 + S2.
Vm * T = Vm * t + Vsv * t.
Vm * T – Vm * t = Vs * t.
Vm = Vsv * t / (T – t).
Vm = 340 m / s * 2 s / (36 s – 2 s) = 20 m / s.
Answer: the motorcyclist was moving at a speed Vm = 20 m / s.