(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Please refer to the figures. (The first one is multiple-choice, the latter is structured).

2. Relevant equations

For the first problem:

u = √(2gH)

x = u_{x}sinθt + [itex]\frac{1}{2}[/itex]gsinθt^{2}

u_{y}cosθt = [itex]\frac{1}{2}[/itex]gcosθt^{2}and maybe others

u = initial velocity

x = x-displacement (along the slope)

y = y-displacement (perpendicular to slope)

For the second:

F_{G}= Gm_{1}m_{2}/ r^{2}

m are masses

r is radius

F_{G}= gravitational attractive force between two masses

[itex]G\ =\ 6.673(10)\ \times\ 10^{-11}\ m^{3} kg^{-1} s^{-2}[/itex]

and maybe others

3. The attempt at a solution

Sorry, I've been doing these two problems for hours, still can't get the answers:

For the first, I only found that the time between the release and the first impact might be √(2H/g).

For the second problem I even dont any idea about how to solve it:(

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# Two hard physics problems (Projectile motion and gravitation), for me

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