Is oxegen abiotic or biotic

Which statement is true for light passing into a medium that is more optically dense than the first medium through which it past

Achild throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal. the ball leaves her hand 1.00 m above the ground. how long is the ball in flight before it hits the ground?

Which type of wave can travel without a medium