If you are pushing the coin across the table at a constant rate, the friction of the table and the horizontal force of your hand pushing are equal, and the coin itself moves at a constant rate. If you push a coin and let it go, there is no horizontal force keeping the coin going. Friction slows the coin to a stop. In both cases, the gravitational downward pull of Earth is equally but oppositely resisted by the upward push of table on the coin.
Answer:
24.3 m/s
Explanation:
1 kmh = 0.27 m/s, that makes a conversion ratio of 0.27/1kmh
x 
The "kmh" n the top and bottom cancel out. And then you just multiply the top 90 x 0.27 and the bottom 1 x 1 to get

and since its over 1 its just 24.3 m/s
Answer:
diameter = 21.81 ft
Explanation:
The gravitational force equation is:

Where:
- F => Gravitational force or force of attraction between two masses
- M => Mass of asteroid 1
- m => Mass of asteroid 2
- R => Distance between asteroids 1 and 2 (from center of gravity)
We also know that the asteroids are identical so their masses are identical:
Since R is the distance between centers of the two asteroids and their diameters are identical (see attachment), we can conclude that:
We don´t know the mass of the asteroids but we know they are composed of pure iron, so we can relate their masses to their density:
This is going to be helpful because the volume of a sphere is:
And know we can write our original force of gravity equation in terms of the radius of the asteroids:
Now let´s plug in the values we know:
mutual gravitational attraction force
gravitational constant
Solve for r and multiply by 2 because 2r = diameter
Result is d = 21.81 Feet