A few questions.
1.)why can we tell that the raindrop also has a negative speed?
2) could you please explain where you get -vsin(theta)i - vcos(theta)j ? and how is Vr/c = that value - Vc/e?
Thank you so much
SM_3490027
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12PRACTICE PROBLEM
A cyclist rides on a rainy day at a steady speed of 7 km/h along the x-axis in the positive direction. The cyclist remarks that the traces of the raindrops are tilted at an angle of 26 degrees clockwise from the vertical direction. Due to the bad weather conditions, she decides to make a U-turn. She moves now at the same steady speed along the x-axis in the negative direction. On her way back, she observes that the traces of the raindrop are now aligned with the vertical. Calculate the speed of the raindrops and their inclination with respect to a fixed frame on earth.
A cyclist rides on a rainy day at a steady speed of 7 km/h along the x-axis in the positive direction. The cyclist remarks that the traces of the raindrops are tilted at an angle of 26 degrees clockwise from the vertical direction. Due to the bad weather conditions, she decides to make a U-turn. She moves now at the same steady speed along the x-axis in the negative direction. On her way back, she observes that the traces of the raindrop are now aligned with the vertical. Calculate the speed of the raindrops and their inclination with respect to a fixed frame on earth.
Robert
Tutor
Hi there!
Using relative velocity, when cyclist moves right (stationary observer), the rain has leftward horizontal velocity and a CW angle.
We observe a reduction in this CCW angle, which implies that the rain has a negative horizontal velocity that cancels 'the positive velocity transferred (transfer refers to relativistic effect where cyclist is stationary and rain takes her velocity) from cyclist to the rain'.
2) Having explained how the rain has negative horizontal velocity, and falls vertically downward (both components relative to Earth), we can write a decomposition equation v = vcos(theta)i + vsin(theta)j... But theta is measured from y-axis (vertical), we swap sin and cos to v = vsin(theta)i + vcos(theta)j. Apply sign of components, v = -vsin(theta)i - vcos(theta)j…