Answer:
<h2>320 N</h2>
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 80 × 4
We have the final answer as
<h3>320 N</h3>
Hope this helps you
When precipitation hits the ground and hydrosphere
Answer:
k = 101.2 N / m
Explanation:
For this exercise we can use the relationship between work and energy
W = ΔK (1)
Where the work of the friction force is
W = fr x cos θ
As the friction force opposes the movement, the angle is 180º, so the kinetic product remains
W = - fr x
The friction force is given by the equation
fr = μ N
Let's use Newton's second law
Axis y
N - W = 0
N = W
We substitute
fr = μ mg
So the work is
W = - μ m g x
On the other hand, the variation in energy is
ΔEm = Em_final - Em_inicial
ΔEm = ½ k x² - ½ m v²
We substitute in our initial equation 1
-μ m g x = ½ k x² - ½ m v²
k = 2m / x² (- μ g x + ½ v²)
k = 2 2.00 / 0.190² (- 0.660 9.8 0.190 + ½ 2.07²)
k = 101.2 N / m
Answer:
30 N
Explanation:
there are two forces act on the bar:
- weight of 1.5 kg mass, w = mg = 15 N
- weight of the bar, wb
for balance,
w * Lw = wb * Lwb
Lw = length of bar from the mass to the pivot
Lwb = lenght of bar from the center of the bar to the pivot
15 * 20 = wb * (50-20)
300 = wb * 30
wb = 300/30 = 30 N
Answer:
b. AG, work function=4.74eV
Explanation:
Ultraviolet light starts at the end of the visible light spectrum, where violet light ends:
(wavelength of lowest-energy ultraviolet light)
So, the lowest energy of ultraviolet light can be found by using the formula
where
h is the Planck constant
c is the speed of light
Substituting,
And keeping in mind that
This energy converted into electronvolts is
The work function of a metal is the minimum energy needed to extract a photoelectron from the surface of the metal. Therefore, the metals that exhibit photoelectric effect are the ones whose work function is larger than the energy we found previously, so:
b. AG, work function=4.74eV
Because for all the other metals, visible light will be enough to extract photoelectrons.