Your potential energy at the top of the hill was (mass) x (gravity) x (height) .
Your kinetic energy at the bottom of the hill is (1/2) x (mass) x (speed)² .
If there was no loss of energy on the way down, then your kinetic energy
at the bottom will be equal to your potential energy at the top.
(1/2) x (mass) x (speed)² = (mass) x (gravity) x (height)
Divide each side by 'mass' :
(1/2) x (speed)² = (gravity) x (height) . . . The answer we get
will be the same for every skater, fat or skinny, heavy or light.
The skater's mass doesn't appear in the equation any more.
Multiply each side by 2 :
(speed)² = 2 x (gravity) x (height)
Take the square root of each side:
<u>Speed at the bottom = square root of(2 x gravity x height of the hill)</u>
We could go one step further, since we know the acceleration of gravity on Earth:
Speed at the bottom = 4.43 x square root of (height of the hill)
This is interesting, because it says that a hill twice as high won't give you
twice the speed at the bottom. The final speed is only proportional to the
<em>square root </em>of the height, so in order to double your speed, you need to
find a hill that's <em>4 times</em> as high.
No clue. bye. and gold luck!
Answer:
The small pebble
Explanation:
Since the potential energy, P.E lost equals kinetic energy, K.E gained,
P.E = K.E
P.E = mgh = K.E
So, K.E = mgh where g = acceleration due to gravity and h = height of drop
Since h and g are constant
K.E ∝ m
So, the kinetic energy of the object is directly proportional to its mass. Thus, the object with the smaller mass has the lesser kinetic energy.
Since the object with the smaller mass is the small pebble, so the small pebble would have less kinetic energy as it crashes on the road at the bottom of the mountain.
D = V1( t ) + 1/2g( t )^2
50m = 0m/s( t ) + 1/2(9.8m/s^2)*( t )^2
V1*t cancels out
50m = (4.9m/s^2)*(t)^2
50m/(4.9m/s^2) = t^2
Metres unit cancels out so we are left with s^2
10.204s^2 = t^2
Square root both sides to cancel out square
t = 3.19 s
I'm pretty sure it's true. Hope it helps!
