A rifle is aimed horizontally at a target on a screen some distance away. The bullet hits the target 2.8 cm below the aim point. The initial velocity of the bullet is 780 m/s. Required:
a. What was the bullet's flight time?
b. What was the bullet's speed as it left the barrel?

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?