Answer:
μ = 0.66, therefore if it compiesy with the regulations
Explanation:
Let's solve this exercise in part, let's start by finding with kinematics the acceleration of man
y = v₀ t + ½ a t²
as it starts from rest the initial velocity is zero
y = ½ a t²
a =
a =\frac{2 \ 4.38}{1.21^2}
a = 6.46 m / s²
Now let's use Newton's second law,
Axis y
N- W = 0
N = W
N = m g
X axis
on this axis the man exerts a backward force and by the law of action and reaction the floor exerts a forward force of the same magnitude, this forward force is the friction force.
fr = m a
the friction force has an expression
fr = my N
let's substitute
μ mg = m a
μ = a / g
let's calculate
μ = 6.46 / 9.8
μ = 0.66
therefore if you comply with the regulations
Answer:
Joule is the name of the unit that are normally used to measure energy
Explanation:
<span>The amount of heat energy needed to increase the temperature of a substance by </span>
<span> is given by:
</span>
<span>
where m is the mass of the substance, Cs is its specific heat capacity and </span>
<span> is the increase in temperature of the substance.
In this problem, we have a certain mass m of gold, with specific heat capacity </span>
<span>, to which we add Q=2825 J of energy. Its temperature increases by </span>
<span>. Therefore, if we re-arrange the previous equation, we can find the mass of the block of gold:
</span>
<span>
So, the correct answer is B.</span>
When you push on a wall, the wall pushes back on you with a force equal in strength to the force you exerted.
Like a then it would be A something I guess it goes like that