2) An archer shoots an arrow horizontally. After 4 seconds it lands on the ground 520m away from the archer.
a) What is the horizontal velocity of the arrow when it is released?

Can someone please answer this right.
b) What is the actual velocity of the arrow when it hits the ground?

You have been hired to design a spring-launched roller coaster thatwill carry two passengers per car. the car goes up a 10-m highhill, then descends 15m to the track's lowest point. you'vedetermined that the spring can be compressed a maximum o 2.0m andthat a loaded car will have a maximum mass of 400kg. for safetyreasons, the spring constant should be 10% larger than the minimumneeded for the car to just make it over the top. a) what spring constant (k) should you specify ? b) what is the maximum speed of a 350 kg car if the spring iscompressed the full amount.