In the circular motion of the hammer, the centripetal force is given by

where m is the mass of the hammer, v its tangential speed and r is the distance from the center of the motion, i.e. the length of the hammer.
Using the data of the problem, we find:
Answer:
A) 0.957 J
Explanation:detailed explanation and calculation is shown in the image below
Speed is not a vector so horizontal speed does not sighify anything. If u meant velocity it vill be same as the initial velocity in horizontal direction
Answer:
μ = 0.350
Explanation:
For the person to able to move the box, the force exerted by the person on the box must equal the force exerted by the box:

In this case, force can be calculated as a product of mass (m) by the acceleration of gravity (g) and the coefficient of static friction (μ):

Therefore, for the person to be able to push the box horizontally, the coefficient of static friction between the box and the floor should not be higher than 0.350.
Heat flows irreversibly from hot to cold