Answer:
1) Speed in m/s equals 22.22 m/s.
2) Speed in miles per hour equals 49.712 mph.
Explanation:
Since we know that in 1 kilometer there are 1000 meters and in 1 hour there are 3600 seconds hence we can write
Now we know that 1 mile equals 1.609 kilometer hence we conclude that 1 kilometer equals 
mile
Hence
We are given the gravitational potential energy and the height of the ball and is asked in the problem to determine the mass of the ball. the formula to be followed is PE = mgh where g is the gravitational acceleration equal to 9.81 m/s^2. substituting, 58.8 J = m*9.8 m/s^2 * 30 m; m = 0.2 kg.
Answer: The answer is C
Explanation:
i did it on usatestprep :)
Answer: O furo diminui enquanto a chapa aumenta a sua dimensão.
(The diameter decreases and the dimensions of the metal increases)
Explanation:
I will answer in English:
Here we have a piece of metal with a small hole on it, that is heated in a hoven.
We know that when a piece of metal is heated, it will expand (the density decreases, so the dimensions of the piece of metal increase).
Now, particularly, the hole will also expand but inwards, as each "extreme" of the piece of metal, will expand into where it has less resistance, so it will expand in the region where there is no material. This "inwards" expansion is why the diameter of the hole will decrease.
They can't hear an echo in small room because in it the sound can't be reflected back. For an echo of a sound to be heard,the minimum distance between the source of sound and the walls of the roomshould be 17.2 m. Obviously,in asmall room echoes cannot beheard.
