Aboy uses a slingshot to launch a pebble straight up into the air. the pebble reaches a height of 37.0 m above the launch point 2.3 seconds later. assume air resistance is negligible (a) what was the pebble's initial speed (just after leaving the slingshot)? m/s (b) how much time did it take for the pebble to first reach a height of 18.5 m above its launch point? s

V0=27.4 m/s; t=0.8 s

Explanation:

Final position y=37.0 m, time = 2.3 s; Initial position is set to be zero. We calculate the initial speed with the kinematics equation:

We solve for initial speed

Now, using the same expression we estimated time to first reach 18.5 m :

Second order equation with solutions

t1=0.8 s and t2=4.8 s

The first time corresponds to the first reach.

im not to sure what it is

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.