Answer:
28.8 meters
Explanation:
We must first determine at which velocity the ball hits the water. To do so we will:
1) Assume no air resistance.
2) Use the Law of conservation of mechanical energy: E=K+P
Where
E is the mechanical energy (which is constant)
K is the kinetic energy.
P is the potential energy.
With this we have 
Where:
m is the balls's mass <- we will see that it cancels out and as such we don't need to know it.
v is the speed when it hits the water.
g is the gravitational constant (we will assume g=9.8
.
h is the height from which the ball fell.
Because when we initially drop the ball, all its energy is potential (and 
) and when it hits the water, all its energy is kinetic (
. And all that potential was converted to kinetic energy.
Now, from we can deduce that 
Therefore v=9.6
Now, to answer how deep is the lake we just need to multiply that speed by the time it took the ball to reach the bottom.
So D=9.6*3
=28.8
Which is our answer.
Answer:
0.84μF
Explanation:
Charge is same through both the capacitors since they are in series. Total voltage is the sum of the voltages of the individual capacitors.. So voltage across the 2nd capacitor is 120- 90 =30 V.
Charge across first capacitor is Q = C₁V₁ = 90 x0.28 = 25.2μC
Therefore capacitance of 2nd capacitor =
C₂ = Q÷V₂ = 25.2÷30 = 0.84 μF
The skier’s change in velocity is 8.33.../8.4 m/s.
21/63= 0.33...
0.33...x 25 s = 8.33.../8.4 m/s
Answer:
W = 1014 J = 1.014 KJ
Explanation:
As, Sam has to stop the boats in the log ride. Therefore, the work Sam needs to do, in order to stop a boat must be equal to the kinetic energy of the boat:
Work Done by Sam = Kinetic Energy of the Boat
W = K.E
W = (1/2)mv²
where,
m = mass of boat and its rider = 1200 kg
v = speed of the boat = 1.3 m/s
Therefore,
W = (1/2)(1200 kg)(1.3 m/s)²
<u>W = 1014 J = 1.014 KJ</u>
Yes an change in velocity either a decrease or increase is an acceleration.
