posted by jake .
An arrow is launched vertically upward from a crossbow at 98.2 m/s. Ignoring air friction, what is its instantaneous speed at the end of 10.0 s of flight?
What is its average speed up to that moment?
How high has it risen?
What is its instantaneous acceleration 4.20 s into the flight?
average speed= (Vi+Vf)/2