Horizontal Bounce

HardPhysElo Quiz #4

8.Horizontal Bounce

+10

A large wedge slides on a horizontal floor. Its top surface is a flat plane inclined at an angle

\theta < 45^\circ

to the horizontal, oriented such that it slopes upward to the right. The wedge moves horizontally to the right at a constant speed

V

. A small ball is dropped from rest from a height

h

directly above a point on the inclined surface. The ball falls and bounces perfectly elastically off the wedge. What must

V

be so that the ball's velocity immediately after the bounce is purely horizontal?

\sqrt{2gh} \tan\theta

\sqrt{2gh} \cot\theta

\sqrt{2gh} \tan(2\theta)

\sqrt{2gh} \cot(2\theta)

\sqrt{2gh}\left(\cot^2\theta-1\right)

to submit answers

Solved by 7 solves

Daily Attempts

1 attempt per day · Resets at midnight UTC

Rules

📐Express numerical answers in SI units unless stated otherwise.

⌨️Type words like 'mu' or 'pi' to auto-render Greek letters.

➗Use '/' for fractions, '^' for exponents, and 'sqrt' for roots.

🔒Once submitted, answers cannot be changed.

⚡First correct solve earns bonus Quarks.

Discuss

Compare approaches with other solvers.