Answer:
μ = 0.179
Explanation:
For this exercise we use the rotational equilibrium condition, where we set a reference system at the top of the ladder where it is in contact with the parent, we will assume the counterclockwise rotations as positive
∑ τ = 0
W_stairs x/2 + W_man x’+ fr y - N x = 0
fr y = -W_stairs x/2 - W_man x’ + N x
let's use trigonometry for distances
* the man up the ladder 78%
l ’= 0.78 L
cos 59 = x ’/ l’
x’= 0.78 L cos 59
* the horizontal distance
cos 59 = x / L
x = L cos 59
* vertical distance
sin 59 = Y / L
y = L sin 59
we substitute
fr L sin 59 = -W_stairs Lcos59 / 2 - W_man 0.78 L cos59 + N L cos59
fr sin 59 = - ½ W_stairs cos 59 - 0.78 W_man cos 59 + N cos 59
fr = ctan 59 (N - ½ W_stairs - 0.78 W_man) (1)
Let's write the translational equilibrium equations
Y axis
N -W_stairs - W_man = 0
N = W_stairs + W_man
N = 85 + 21.5 9.8
N = 295.7 N
we substitute in 1
fr = ctg 59 (295.7 - ½ 85 - 0.78 21.5 9.8)
fr = 0.6 (295.7 - 42.5 - 164.346)
fr = 52.89 N
the expression for the friction force is
fr = μ N
μ = fr / N
μ = 52.89 / 295.7
μ = 0.179
PLZZZZZZZZZ HELPPPPP. BRAINLEST GIVEN What is a force of attraction between an object and the earth due to gravity?
Answer:
acceleration due to gravity: -9.8 m/s^2
Fg=mass of object*(-9.8)
Explanation:
This is a pretty vague question, but I'll answer as best I can.
All matter has gravity. YOU have gravity, although your gravitational pull is small. So, the force of attraction between the Earth and an object on Earth is modeled as
Force of gravity=(Gravitational constant*mass of object 1*mass of object 2)/distance between objects squared
Note that distance between an object on Earth and Earth is the radius of Earth (distance to Earth's core/center of mass)
How many planets are there in our System? List them all.
Answer:
Eight planets.
1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune
When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 84.0-kg man just before contact with the ground has a speed of 6.82 m/s. (a) In a stiff-legged landing he comes to a halt in 4.56 ms. Find the magnitude of the average net force that acts on him during this time. (b) When he bends his knees, he comes to a halt in 0.254 s. Find the magnitude of the average net force now. (c) During the landing, the force of the ground on the man points upward, while the force due to gravity points downward. The average net force acting on the man includes both of these forces. Taking into account the directions of the forces, find the magnitude of the force applied by the ground on the man in part (b).
Answer:
a) F = 1.26 10⁵ N, b) F = 2.255 10³ N, c) F_ {soil} = 3078 N
Explanation:
For this exercise we will use the relationship between momentum and moment
I = Δp
F t = p_f -p₀
a) with stiff legs, final speed is zero, initial velocity is down
Ft = 0-p₀
F = m v / t
let's calculate
F = 84.0 6.82 / 4.56 10⁻³
F = 1.26 10⁵ N
b) bending the legs
let's calculate
F = 84.0 6.82 / 0.254
F = 2.255 10³ N
c) It is requested to calculate the force of the ground on the man
∑ F = F_soil -W
F_soil = F + W
F_ {soil} = 2.255 103 + 84 9.8
F_ {soil} = 3078 N
Suppose to a scientist was able to construct a barometer with a liquid being twice denser than mercury, then how would the liquid raise at standard pressure?
Answer:
h = h₀/2, the liquid column rises half the height
Explanation:
Pressure is defined as force per area,
P = F / A
in a barometer the force is the weights of the liquid column
F = W = mg
P = m g/A
if we use the definition of density
ρ = [tex]\frac{m}{A h}[/tex]
[tex]\frac{m}{A}[/tex] = ρ h
we substitute
P = ρ g h
Let's use the index o for the mercury
P₀ = ρ₀ g h₀
when we change the liquid for another with
ρ = 2ρ₀
the pressure expression is
P = 2ρ₀ g h
in the problem they indicate that the pressure is equal to the initial P = P₀
we substitute
ρ₀ g h₀ = 2ρ₀ g h
h₀ = 2h
h = h₀/2
the liquid column rises half the height
It is common for creatures to be able to live in both the spray zone and low-tide zone.
True or False
Hii!!! The correct answer is true. (:
two uses of electricity
You throw a basketball from a cliff to the ground. The ball has an initial velocity of 12 m/s in the horizontal direction. After 3.0 seconds, the ball has a velocity of -30.0 m/s in the y-direction.
What is the direction of motion of the ball at time t= 3.0 s? (Hint: direction is related to the angle).
Answer:
The direction of motion of the ball is approximately 68.199º below the +x semiaxis.
Explanation:
The ball has a two-dimension motion, to be exact, a parabolical motion, that is, a motion at constant velocity in the x-direction and free fall motion in the y-motion. Hence, the horizontal velocity of the basketball is 12 meters per second and its direction ([tex]\theta[/tex]), in sexagesimal degrees, is calculated by this trigonometrical expression:
[tex]\theta = \tan^{-1} \frac{v_{y}}{v_{x}}[/tex] (1)
Where:
[tex]v_{x}[/tex] - Horizontal velocity, in meters per second.
[tex]v_{y}[/tex] - Vertical velocity, in meters per second.
If we know that [tex]v_{x} = 12\,\frac{m}{s}[/tex] and [tex]v_{y} = -30\,\frac{m}{s}[/tex], then the direction of motion of the ball is:
[tex]\theta \approx 68.199^{\circ}[/tex] (below the +x semiaxis)
The direction of motion of the ball is approximately 68.199º below the +x semiaxis.
A glass window (n = 1.52) has a
uniform layer of ice on it (n = 1.31).
What is the critical angle for a ray
trying to pass from glass to ice?
(Water n = 1.33, Air n = 1.00)
(Unit = deg)
HELP PLSS!!
Answer: 59.5 deg
Explanation: In this problem, we are giving 1.31 as n2 and 1.52 as n1. Using the formula of critical angle= arcsine(n2/n1) we get the equation critical angle=arcsine(1.31/1.52) from there, you divide 1.31 by 1.52, and get 0.862.
On your calculator you then should press 2nd and then the sine button to get sine^-1 (arcsine) and in the parenthesis after arcsine put in 0.862, the answer you get will be 59.5.
What is the relationship between retar ding potential and the kinetic energy of the emitted photoelectrons?
Answer:
The kinetic energy of photoelectrons at the surface grows linearly with the increasing frequency of incident radiation. Measurements for all metal surfaces give linear plots with one slope.
The reason that worlds like the Earth are differentiated is that Group of answer choices the heat of the Sun vaporized much of their solid material early on the heaviest chunks that hit early on were able to bore through solid rock to the center the continuing impacts on a growing protoplanet eventually melted the entire body large amounts of hydrogen and helium collect around such planets a little later in their history planetesimals with different types of composition hit at different times, with the heaviest ones hitting first
Answer:
A differentiated body is a body that has been heated to the point where it is are further from the sun larger have no solid surface and have many more moons Smaller chunks of material vaporize completely as they pass through its atmosphere
Explanation:
Hope it helps..A body is said to be differentiated when it has been heated to the extent where it is bigger, farther from the sun, has no hard surface, and has a lot more moons. Smaller pieces of the materials entirely evaporate as they pass through their environment.
What is Planet?An enormous, spherical celestial object known as a planet is neither a star nor a remain. The nebular theory, which states that an interstellar cloud collapses out of a nebula to form a young protostar that orbits the sun by a protoplanetary disk, is now the best argument for planet formation. By slowly accumulating material under the influence of gravity, or accretion, planets form in this disk.
The terrestrial planets Mercury, Venus, Earth, and Mars, as well as the planetary nebulae Jupiter, Saturn, Uranus, and Neptune, total at least eight planets in the Solar System. These planets all rotate around axes that seem to be inclined relative to their corresponding polar axes.
To know more about Planet:
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Plzzzz help hurry plzzzzzz plzzz
Answer:
The first one is C, and the second is not clear please show another photo
Explanation:
rulers graduated in centimeters and inches are available in commerce. Determine the measurement in m of a 60 cm ruler can you help me
Answer:
0.6m
I hope this help a little bit.
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Michael is driving to Starbucks from his house. He walks 9 miles South to pick up his latte. He then drives 10 miles east to COHEA. What is the displacement of Devin?
Answer:
Displacement = [tex]13.45\ \text{miles}[/tex]
Explanation:
Given that,
Michael walks 9 miles South to pick up his latte. He then drives 10 miles east to COHEA.
We need to find the displacement of Michael. We know that displacement is the shortest path covered by the object. In this case, it is given by :
[tex]d=\sqrt{10^2+9^2} \\\\d=13.45\ \text{miles}[/tex]
So, the displacement of Michael is equal to [tex]13.45\ \text{miles}[/tex].
Calculate the amount of heat needed to convert 0.8 kg of ice at -19 °C into water at 29 °C.
will mark the brainiest
why is water poor conductor of heat but food conductor of electricity? pls explain
Explanation:
water contains dissolved salts which can create ions
Answer:
Water is a poor conductor of heat: Most of the heat will move in a convection current within the water at the top of the test tube, only a small fraction of it will conduct down to the ice cube.
Water doesn't need to have a large amount of impurities to act as a good conductor of electricity; even a small amount of ions can enable a source of water to conduct electric current. In a nutshell, water is able to conduct electricity due to the dissolved ions and impurities within it.
Complete the following sentence.
An animal’s genetic and observable traits are called the
_and_
dont have options
Answer:
Dominant and recessive
Explanation:
This is like 6th-grade stuff man
if a car exerts a area of 3m and a force of 9N what is the pressure exerted by car
Answer:
P = 3 Pa
Explanation:
Given that,
Force exerted by the car, F = 9 N
The area of the car, A = 3 m²
We need to find the pressure exerted by the car. We know that pressure is equal to the force per unit area such that,
[tex]P=\dfrac{F}{A}\\\\P=\dfrac{9\ N}{3\ m^2}\\\\P=3\ Pa[/tex]
So, the pressure exerted by the car is equal to 3 Pa.
7. a. How is speed related to kinetic energy?
Increase in speed leads to increase in kinetic energy
Which graph best represents the relationship between KE and speed?
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward.
A graph with vertical axis K E and horizontal axis Speed with a concave line sloping sharply upward.
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply downward.
A graph with vertical axis K E and horizontal axis Speed with a curved line going first upward and then downward.
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward.
Relationship between kinetic energy and speedThe kinetic energy of an object is directly proportional to the square of its speed which means that if kinetic energy of an object increases the speed of that object is also increases and vice versa so we can conclude that graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward is the right answer.
Learn more about speed here: https://brainly.com/question/4931057
Answer:
The correct answer is:
B.)
Explanation:
I did the assignment on Edge, 2022.
(See the attachment below.)
Hope this helped, good luck on the quiz! :D
The 500 series bullet train travels between Tokyo and Hakata, Japan. If it is heading north with a momentum of 13,194,098.64 kg • m/s and at a velocity of 261.8 km/h, what is its mass?
Answer:
The mass of the 500 series bullet train is 181.4 tonnes.
Explanation:
The momentum is given by:
[tex] p = mv [/tex]
Where:
m: is the mass =?
v: is the velocity = 261.8 km/h
p: is the momentum = 13194098.64 kg*m/s
By solving the above equation for "m" we have:
[tex]m = \frac{p}{v} = \frac{13,194,098.64 kg*m/s}{261.8 km/h*\frac{1000 m}{1 km}*\frac{1 h}{3600 s}} = 181.4 tonnes[/tex]
Therefore, the mass of the 500 series bullet train is 181.4 tonnes.
I hope it helps you!
Forms of energy! Write a brief summary about each form of energy below.
Mechanical:
Thermal:
Chemical:
Electromagnetic:
Electrical:
Nuclear:
Answer:
Hope this helps!! :D
Explanation:
Mechanical energy is power that an object gets from its position and motion. the energy released during nuclear fission or fusion, typically to make electricity.
Thermal energy is the energy given off by hot things like fire.
Chemical energy is energy stored in the bonds of chemical compounds.
Electromagnetic energy is a form of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel.
Electrical energy is energy derived from electric potential energy or kinetic energy.
Nuclear energy is the energy released during nuclear fission or fusion, typically used to generate electricity.
Daylon's family just bought a new puppy, and Daylon decided to take him for a walk. He put the puppy in a wagon and pulled the wagon along the sidewalk. From which of these reference points does the puppy appear to be moving? 1. Daylon 2. The wagon 3. The sidewalk 4. The puppy's collar
The puppy was not moving relative to Daylon, the wagon, or his collar.
He was moving relative to a point on the sidewalk.
Note that the puppy did NOT get his walk.
How has the work of various scientists helped us understand and create the current model of the atom?
why joule is called derived unit?
Answer:
It is also the energy dissipated as heat when an electric current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889).
Explanation:
Una varilla efectúa 120 vibraciones durante un minuto. Hallar el período y la frecuencia del movimiento
A student makes a homemade resistor from a graphite pencil 5.00 cm long, where the graphite is 0.05 mm in diameter. The resistivity of the graphite is rho=1.38×10−5Ω/mrho=1.38×10−5Ω/m . The homemade resistor is place in series with a switch, a 10.00-mF uncharged capacitor and a 0.50-V power source. (a) What is the RC time constant of the circuit? (b) What is the potential drop across the pencil 1.00 s after the switch is closed?
Answer:
(a) RC time constant of the circuit is 6.9 × 10⁻⁶ ms
(b) The potential drop across the capacitor 1.00 s after the switch is closed is 0 V
Explanation:
The given parameters are
The length of the graphite pencil, L = 5.00 cm
The diameter of the graphite, D = 0.05 mm
The resistivity of the graphite, ρ = 1.38 × 10⁻⁵ Ω/m
The capacitance of the capacitor, C = 10.0 mF
The voltage of the power source, V = 0.50-V
(a) The RC time constant of the circuit, τ, is given as follows;
τ = R × C
Where;
R = The resistance of the graphite = L × ρ
C = The capacitance of the capacitor
∴ R = 5.00 cm × 1.38 × 10⁻⁵ Ω/m = 6.9 × 10⁻⁷ Ω
RC time constant of the circuit, τ = 6.9 × 10⁻⁷ Ω × 10.0 mF = 6.9 × 10⁻⁶ ms
RC time constant of the circuit, τ = 6.9 × 10⁻⁶ ms
(b) The potential drop after t = 1.00 s is given as follows;
[tex]i = \dfrac{V}{R} \cdot e^{-\dfrac{t}{R\cdot C} }[/tex]
Where;
I = The current in the circuit
V = The voltage in the circuit = 0.50 V
R = resistance in the circuit = 6.9 × 10⁻⁷ Ω
C = The series capacitance = 10.0 mF
t = The time taken = 1.00 s
Plugging in the variable values, gives;
[tex]I = \dfrac{0.5}{6.9 \times 10^{-7}} \cdot e^{-\dfrac{1.00}{6.9 \times 10^{-7}\times 10.0 \ mF} } = 0[/tex]
V(1) = I·R = 0 × R = 0
The potential drop across the capacitor 1.00 s after the switch is closed, V(1) = 0 V
n the railroad accident, a boxcar weighting 200 kN and traveling at 3 m/s on horizontal track slams into a stationary caboose weighting 400 kN. The collision connects the caboose to the car, and then both move together and you have found the final velocity. Apparently, initial kinetic energy of the system changes (in part, because of friction present). How much energy (in kJ) is transferred from kinetic energy to other forms of energy (e..g., thermal) in the collision
Answer:
ΔK = -6 10⁴ J
Explanation:
This is a crash problem, let's start by defining a system formed by the two trucks, so that the forces during the crash have been internal and the moment is preserved
initial instant. Before the crash
p₀ = m v₁ + M 0
final instant. Right after the crash
p_f = (m + M) v
p₀ = p_f
mv₁ = (m + M) v
v = [tex]\frac{m}{m+M} \ v_1[/tex]
we substitute
v = [tex]\frac{20}{20+40}[/tex] 3
v = 1.0 m / s
having the initial and final velocities, let's find the kinetic energy
K₀ = ½ m v₁² + 0
K₀ = ½ 20 10³ 3²
K₀ = 9 10⁴ J
K_f = ½ (m + M) v²
K_f = ½ (20 +40) 10³ 1²
K_f = 3 10⁴ J
the change in energy is
ΔK = K_f - K₀
ΔK = (3 - 9) 10⁴
ΔK = -6 10⁴ J
The negative sign indicates that the energy is ranked in another type of energy
In a ride in an amusement park, a carriage of mass 450 kg is travelling horizontally at a speed of 18 m/s. It passes through a shallow tank containing stationary water. The tank is of length 9.3 m. The carriage leaves the tank at a speed of 13 m/s. PT 3 a.) Calculate the change in kinetic energy of the cart while it passes through the water tank J (Hint: Change
Answer:
98.
Explanation:
divide
The change in the kinetic energy of the cart is equal to 34875 J.
What is kinetic energy?The energy which is possessed by a moving body because of its motion is known as kinetic energy. Work should be done in order to bring the change in the kinetic energy of a moving object.
The kinetic energy of a moving object can be determined from the formula mentioned below:
K.E. = ½mv² where ‘m’ and 'v' is the mass and velocity of the object.
Given, the mass of the carriage, m = 450 Kg
The speed of the carriage, u = 18 m/s
The initial kinetic energy of the cart = (1/2) × 450 × (18)²
(K.E.)₁ = 72900 J
The final speed of the cart, v = 13 m/s
The final kinetic energy of of the cart = (1/2) × 450 × (13)²
(K.E.)₂ = 38025 J
The change in the kinetic energy of the cart = (K.E.)₂ - (K.E.)₁
Change in the kinetic energy = 72900 - 38025 = 34875 J
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If a force of 3000 N can move a crate at an acceleration of 9.2 m/s2, what is the mass of the object?
Answer:
326 kg
Explanation:
m=f/a
3000/9.2=326 kg