Answer:

Explanation:
From the question we are told that:
Frictional force 
Coefficient of kinetic friction 
Generally the equation for Normal for is mathematically given by

Therefore


Answer:
D. ) The force would be zero newtons
Explanation:
Because
If you are at the center of the earth, gravity is zero because all the mass around you is pulling "up" (every direction there is up!)
So F=mg so if g is zero F is also zero
A roller coaster car starts from the rest from a first summit, descends a vertical distance of 45 meters and then climbs a second summit, reaching the top with a speed of 15m / s. How high is the second summit? Do not consider friction
Electromagnets have certain advantages over permanent magnets. One of the major advantage is, the amount of electric current can easily be controlled, in turn, magnetic field can be controlled. Out of all the options, option D would be the best answer.
In short, Your Answer would be option D) Electromagnets can easily be turned on and off.
Hope this helps!
The formula for the density of a substance expressed in mass and volume is rho = mass/volume or p = m/v. Rearranging the formula to isolate volume gives the formula v = m/p. To solve for the problem given, this formula must be used. This gives a solution of:
v = m/p = 250 g/ 968 g/cm^3 = 0.258 cm^3 of sodium