A STONE IS DROPPED FROM A CLIFF SOME HIGH. DISREGARDING AIR RESISTENCE, (a) HOW LONG DOES IT TAKE THE STONE TO REACH THE GROUND? (b) WHAT IS ITS SPEED WHEN IT STRIKE THE AROUND?
You need to provide numbers like the cliff height. "Some high" won't cut it.
Please turn off your caps lock. It is like being yelled at.
I assume you are looking for a general expression for the time it takes an object to fall from a cliff of height "h".
From h = Vot + gt^2/2
where H = the height of the cliff
Vo = the initial velocity = 0
g = acceleration due to gravity and t = the time of the fall.
Solving for t yields
t = sqrt(2h/g).
Choose your "h" and you have the time of the fall.
h=100m t=200/9.8= 20.408 sec.
Nothing foo
To find the answer to the question, we can use the laws of motion, specifically the equations of motion under constant acceleration. In this case, the stone is dropping due to gravity, so it is subject to constant acceleration.
(a) To calculate how long it takes for the stone to reach the ground, we can use the equation:
s = ut + (1/2)at^2
where:
s = distance traveled (height of the cliff)
u = initial velocity (0 m/s, as the stone starts from rest when dropped)
a = acceleration due to gravity (-9.8 m/s^2, assuming downward direction)
t = time taken
Since the stone is dropped from rest, its initial velocity is 0. Therefore, the equation becomes:
s = (1/2)at^2
Rearranging the equation to solve for time, we have:
t = sqrt(2s/a)
Given the height of the cliff, you can substitute the value and calculate the time it takes for the stone to reach the ground.
(b) To find the speed of the stone when it strikes the ground, we can use another equation of motion:
v = u + at
where:
v = final velocity (which is the speed when the stone strikes the ground)
u = initial velocity (0 m/s)
a = acceleration due to gravity (-9.8 m/s^2)
t = time taken (calculated in part (a))
Substituting the values into the equation, you can find the speed at which the stone strikes the ground.
Remember, this calculation assumes the absence of air resistance. In reality, air resistance would affect the actual time taken and the final speed of the stone.