Answer:
The force needed is the weight of the rock minus the buoyant force.
Explanation:
Answer:

Explanation:
From the question we are told that:
Force P=88Ib
Mass of crate M_c=210Ib
Generally the equation for Frictional force F is mathematically given by


with 

Therefore since Static Friction supersedes applied force body remains at rest.
Frictional force =88Ib (negative)

Answer:
a) 
Explanation:
a) Let assume that the ground is not inclined, since the bottom of the playground slide is tangent to ground. Then, the length of given by the definition of a circular arc:



The bottom of the slide has a height of zero. The physical phenomenon around Dr. Ritchey's daughter is modelled after Principle of Energy Conservation. The child begins at rest:


The average frictional force is cleared within the expression:

![f = \frac{(12\,kg)\cdot [(9.807\,\frac{m}{s^{2}} )\cdot (3\,m)-\frac{1}{2}\cdot (4.5\,\frac{m}{s} )^{2} ]}{6.676\,m}](https://tex.z-dn.net/?f=f%20%3D%20%5Cfrac%7B%2812%5C%2Ckg%29%5Ccdot%20%5B%289.807%5C%2C%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D%20%29%5Ccdot%20%283%5C%2Cm%29-%5Cfrac%7B1%7D%7B2%7D%5Ccdot%20%284.5%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29%5E%7B2%7D%20%5D%7D%7B6.676%5C%2Cm%7D)

Speed = distance / time.
Speed of him leaving the nest:
S = 100 / 20sec
5 m/s.
Catching the snake:
S2 = 50 / 5sec
10 m/s.
Average of 5& 10 = 7.5
7.5 m/s has to be the answer.