Answer:
Explanation:
Given
initially mass is stretched to 
Let k be the spring Constant of spring
Therefore Total Mechanical Energy is 
Position at which kinetic Energy is equal to Elastic Potential Energy


it is given

thus 



Answer:
c. The coefficient of kinetic friction is less than the coefficient of static friction
Explanation:
When the box finally does break loose. Then the component of the box weight which is parallel to the board weight parallel component, is equal to the
.

For the box to acce;erate thee must be non-zero net force acting on the box parallel to the board. Or we can say,

Therefore the force of kinetic friction must be less than the force of static friction. Thus,

Answer:
see explanations below
Explanation:
At the point when the car leaves the track, the reaction on the road is zero, meaning that the centrifugal force equals the gravitation force, namely
mv^2/r = mg
Solve for v in SI units
v^2 = gr = 9.81 m/s^2 * 14.2 m = 139.302 m^2/s^2
v = sqrt(139.302) = 11.8 m/s
Answer: at 11.8 m/s (26.4 mph) car will leave the track.
H2 or H:H
hope this helps