In phase would mean both waves are at a positive peak, out of phase would mean one is at a positive whilst the other is at a negative. Out of phase would mean the waves cancel each other out
Ok so this is simple projectile motion problem.
if we have an object falling in free fall it is subject to gravity of -9.80m/s^2
so it says it takes 6 sec to fall and we know initial velocity was zero so we know that h=vt+1/2gt^2 so we get h=0+1/2*9.80*6^2 = 176.4m
so solving for final speed we get KE=PE = 1/2mv^2=mgh = 1/2v^2=gh so
v=sqrt(2*g*h) = sqrt(2*9.8*176.4m) = 58.8m/s final speed when it hits the ground
hope this helps you! Thanks!!
Answer:
c) 10.7m/s
Explanation:
From the exercise we know that at 5m the ball is traveling at 4m/s
To calculate its initial velocity we need to solve the following equation:
Since the initial height is 0
Solving for 
They use Newton to measure force
