The board is 2.50m high.
Why?
We can calculate how high was the board applying the Law of Conservation of Mechanical Energy. This Law states that the mechanical energy (kinematic and potential) will be conserved during the motion.
It can be described with the following formula:


At the top of the boar, the kinetic energy is equal to 0.
At the water, the potential energy is equal to 0.
So,

Hence, we have that the board is 2.50m high.
Have a nice day!
Answer:
B.the speed at which the disturbance propagates
a great example would be sound. In air, the speed of sound is about 343m/s, but in iron, the speed of sound is about 5120 m/s that's about 15 times faster than air. Why is this? Well, it is because in the air the molecules are very spread out and have a long way to travel before they can bump their neighbors. But in iron, the molecules are much much closer and have a shorter distence before they hit their neighbors.
Answer:
(D) x = 93.8 m
Explanation:
v^2 = v0^2 + 2ax
(20 m/s)^2 = (5 m/s)^2 + 2(2 m/s^2)x
Solving for x,
x = 93.8 m
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Explanation:
It is given that,
Power consumed by toaster oven, 
Time taken, t = 6 minutes = 0.1 hour
Energy used by toaster, 

Similarly,
Power consumed by toaster oven, 
Time taken, t = 9 minutes = 0.15 hour
Energy used by toaster, 

Hence, this is the required solution.