20. How do astronomers use Hydrogen's unique spectral patterns to determine that the Sun's outer almosphere is primarily Hydrogen?
The white light that reaches Earth
has only the colors of Hydrogen
b. is missing the colors of Hydrogen
c. is primarily made of Hydrogen
d. has the pattern of all other gasses except Hydrogen

The ballistic pendulum was invented in 1742 by english mathematician benjamin robins. it consists of an initially stationary pendulum that moves after being struck by a bullet, and it is used to measure the original velocity of the bullet. the known variables are the bullet's mass m, the pendulum's mass m, and the height to which the block and bullet swing, determined by the length of the pendulum l and final angle θ. two principles of physics are necessary to solve for the bullet's original velocity. what are these principles? conservation of momentum and newton's third law conservation of energy and conservation of angular momentum grade summary deductions 0% potential 100% conservation of momentum and newton's second law. newton's second law and conservation of angular momentum. conservation of energy and newton's third law conservation of momentum and conservation of angular momentum. conservation of momentum and conservation of energy conservation of energy and newton's second law.

Acricket ball of 70g moving with a velocity of 0.5 m/s is stopped by a player in 0.5s what is the force applied to stop the ball

Time remainin52: 42the chart shows data for a moving object.which conclusion is best supported by the information inthe chart? time (s)velocity (m/s