# Under what conditions, will a projectile motion follow a half circle?

What came to my mind is to throw an object far from the earth with a particular speed equal to $$V_{sat}=\sqrt{\frac{G\times M_{central}}{R}}$$like satellites. However, it would follow a full circle.

• You have to specify the height at which it is launched in order to find out when it is going to hit the ground. Nov 9, 2013 at 16:53

This is 1st order approximation, but find the time $t$ to drop a certain height $h$ under approximately constant gravity, and the find the speed needed to go around the 1/2 earth in this time.