Given that,
Mass of a boy = 50 kg
The coefficient of static friction = 0.68
To find,
Let us assume we need to find the maximum static friction between the boy and the ground.
Solution,
The formula for the maximum static friction between the two objects is given by :

Where
N is normal force
Substitute all the values,

Therefore, the maximum static friction between the boy and the ground is 340 N.
Answer: b. Electrons move from glass to silk
Explanation:
When the glass rod is rub over against the silk, the glass loses the electrons due to the physical contact with the silk and the friction so produced. The surface of the glass becomes positively charged and the surface of the silk becomes negatively charged. As the surface of the glass loses electrons which are accepted by the silk surface.
Answer:
the answer is helium you already know that because im in college on my way to the military next week bless me
Explanation:
Answer: It takes 2.85 seconds.
Explanation: according to the question, the kinematics equation for vertical motion is

y₀ is the initial postion and equals 0 because it is fired at ground level;
v₀ is the initial speed and eqauls 14m/s;
g is gravity and it is 9.8m/s²;
y(t) is the final position and equals 0 because it is when the pumpkin hits the ground;
Rewriting the equation, we have:
0 + 14t -
= 0
14t - 4.9t² = 0
t(14 - 4.9t) = 0
For this equation to be zero,
t = 0 or
14 - 4.9t = 0
- 4.9t = - 14
t = 
t = 2.86
It takes 2.86 seconds for the pumpkin to hit the ground.
The source of acceleration (without gravity) is transfer of energy from one object to another or change of its own energy structure so that one of its components changes into increasing energy of motion.
But gravity occurs with no measurable energy transfer nor is the gravitating mass changing its energy structure in order to produce gravity.
If the cause of acceleration and gravity is not related at all is the Equivalence principle just a coincidence that the resulting effects are physically identical and indistinguishable