Question 106468This question is from textbook Mechanics I
: I was not sure about the topic...the topic would be Kinematic equations and gravity free fall but i couldnt find it :(
There are 2 questions, they interlink because they both have heights above the ground that something took off from
Question 5 is, A stone is catapulted vertically upwards with a velocity of 25ms-1 from a point 2 metres above the ground. Find, (a) its velocity when it hits the ground and (b) the time it takes to reach the ground.
Question 7 is a like, a ball is thrown vertically upwards with a speed of 29ms -1. It hits the ground 6 seconds later. By modelling the ball as a particle find the height above the ground from which it was thrown.
I could do question 1,2,3,4 and 6.
But 5 and 7 include the height above and theres an extra step i need to do which i cant find, if some one could help me with question 5 a and b, and question 7, then hopefully i can find a link! :D Thanks alot in advance! :D
This question is from textbook Mechanics I
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website! the general equation is h=(-gt^2)/2+(v0)t+h0; where h=height, g=gravitational acceleration, v0=initial velocity, h0=initial height, and t=time of flight
for 5), solve the general equation for t when h=0 (on the ground)
...then use v=-gt+v0 to find the impact velocity
for 7), you know all the values except for h0 in the general equation, so just plug in
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