Answer:
If a car skids 66 ft on wet concrete, it will move at 243 ft/s when the brake is applied.
Explanation:
To determine how fast the car was moving, after skidding, the formula below is used:
V = √32*fd
V is the car's speed (ft/s)
d is skid length (ft) = 66 ft
f is the coefficient of friction determined by the material the car was skidding on.
Coefficient of friction for wet concrete is 0.65
V = √32*fd
V = √32 *0.65* 66
V = 242.679 ft/s ≅ 243 ft/s (nearest whole number)
If a car skids 66 ft on wet concrete, it will move at 243 ft/s when the brake is applied.
<span>The relative hardness of a mineral
can be tested by the Moh’s scale or the mineral hardness. The Moh’s scale can
be characterized by the ability of the mineral to resist scratch resistance by
scratching a harder or softer mineral. It has a scale of 1 to 10 where 1 being
the softest and 10 being the hardest. The relative hardness of a mineral can
best be tested by scratching the mineral across a glass plate. The answer is
letter A. </span>
Well, st first we should find <span>initial momentum for the first person represented in the task which definitely must be :
</span>

And then we find the final one :

Then equate them together :
So we can get the velocity, which is

In that way, according to the main rules of <span>conservation of momentum you can easily find the solution for the second person.
Regards!</span>
Speed=30 m/s - 1.5 m/s = 28.5 m/s forward