In order to calculate frictional force look below..
The formula given by
[tex]\\ \sf\longmapsto F_f=\mu N[/tex]
Or
[tex]\\ \sf\longmapsto F_f=\mu mg[/tex]
u is coefficient of friction
N is normal reaction.
a place-kicker must kick a football from a point 36.0 m (about 40 yards) from the goal. half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. when kicked, the ball leaves the ground with a speed of 23.9 m/s at an angle of 51.5 degrees to the horizontal. (a) by how much does the ball clear or fall short of clearing the crossbar?
(b) does the ball approach the crossbar while still rising or while falling?
Explanation:
Let's calculate the components of the football's velocity:
[tex]v_{0x} = (23.9\:\text{m/s})\cos{51.5°} = 14.9\:\text{m/s}[/tex]
[tex]v_{0y} = (23.9\:\text{m/s})\sin{51.5°} = 18.7\:\text{m/s}[/tex]
a) The time it takes for the football to travel 36.0 m horizontally is
[tex]t = \dfrac{x}{v_{0x}} = \dfrac{36.0\:\text{m}}{14.9\:\text{m/s}} = 2.4\:\text{s}[/tex]
During this time, the y-displacement of the football is
[tex]y = v_{0x}t - \frac{1}{2}gt^2[/tex]
[tex]\:\:\:\:= (18.7\:\text{m/s})(2.4\:\text{s}) - \frac{1}{2}(9.8\:\text{m/s}^2)(2.4\:\text{s})^2[/tex]
[tex]\:\:\:\:= 16.7\:\text{m}[/tex]
This means that the football cleared the crossbar by 16.7 m - 3.05 m = 13.7 m
b) To determine whether the football was rising or falling while clearing the crossbar, let's look at the y-component of its velocity after 2.4 s:
[tex]v_y = v_{0y} - gt = 18.7\:\text{m/s} - (9.8\:\text{m/s}^2)(2.4\:\text{s})[/tex]
[tex]\:\:\:\:\:\:= -4.82\:\text{s}[/tex]
Since its sign is negative, this means that the football was already on its way down.
3)
Car A, moving in a straight line at a constant speed of 20. meters per second, is initially 200
meters behind car B, moving in the same straight line at a constant speed of 15 meters per
second. How far must car A travel from this initial position before it catches up with car B?
A)
200 m
B)
1000 m
C)
800 m
D)
400 m
Answer:
C) 800
Explanation:
Help !!!
I solved Anthor one but didn’t understand this one ??
Answer:
Explanation:
It's a velocity•time chart. As distance = vt, the area under the curve between limits is the distance traveled.
Pic is fuzzy so I will ASSUME the horizontal axis is seconds and vertical is meters per second.
0 s ≤ t ≤ 5 s = ½(5 - 0)(30 - 0) = 75 m
5 s ≤ t ≤ 10 s = (10 - 5)(30 - 0) = 150 m
10 s ≤ t ≤ 15 s = ½(30 + 20)(15 - 10) = 75 m
0 s ≤ t ≤ 25 s = 75 + 150 + 75 + 20(20 - 15) + ½(20)(25 - 20) = 450 m
help with this question please.
Answer: Yes Because it matches with the mass and the amount of force Hope this helps :>
Explanation:
HELP!!! I HAVE NO IDEA!!!!!!!!!!!!!
1. A rocket has a mass of 0.8 kg and an engine that provides 100 N of force. A second rocket is being designed to use the same engine but accelerate at half the rate of the first rocket. What is the mass of the second rocket?
a. 0.4 kg
b. 1.6 kg
c. 2.4 kg
d. 0.8 kg
2. Which of the following would be a situation with unbalanced forces?
a. Two people pulling on the same side of a wheelbarrow
b. A team of players in tug of war pulling on the rope, each team with equal numbers of people pulling with equal strength
c. Two people of opposite sides of a big tire. One pushes the tire and one pulls it with equal force
d. Two people not touching a crate that is sitting stationary.
3. Why is it generally easier to push a heavy object that is already moving instead of the same heavy object that is stationary
a. The force of gravity on the object is different if it is stationary or not.
b. The force of friction on the object is different if it is stationary or not
c. The force of the push on the object is different if it is stationary or not
d. The normal force on the object is different if it is stationary or not.
Thanks In Advance!! (I will mark brainliest) :)
Answer:
Explanation:
The engine should create the same force
1) F = ma
F = M(½a)
therefore
ma = ½Ma
m = ½M
M = 2m
M = 2(0.8)
M = 1.6 kg
2) Unbalanced forces
a. Two people pulling on the same side of a wheelbarrow
c. Two people of opposite sides of a big tire. One pushes the tire and one pulls it with equal force
3) b. The force of friction on the object is different if it is stationary or not
What is the magnitude of the electric field at a point 0.0075 m from a 0.0035
C charge?
Use E-
kq
and k - 9.00 x 10° N.m²/C2.
A. 1.9 x 1010 N
B. 4.2 x 10' N
O c. 5.6 x 1011 N
D. 5.5 x 1012 N
Explanation:
E = 9×10^9 × 0.0035 /(0.0075)²
= 9×10^9 × 3.5×10`³/(7.5×10`³)²
= 31.5×10^6 /(56.25 ×10^-6)
= 0.56 × 10^12
= 5.6 × 10^11 N/C (option C)
Which material(s) listed below is an example of a persistent organic pollutant?
(*select all that apply)
Select 4 correct answer(s)
Ricin
PCBs
DDT
Mercury
Arsenic
Answer:
mercury
arsenic
ricin
ddt
Explanation:
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Among the materials listed, examples of persistent organic pollutants (POPs) are PCBs (Polychlorinated Biphenyls) DDT (Dichlorodiphenyltrichloroethane). The correct option is (2) and (3).
Persistent Organic Pollutants (POPs) are a class of chemicals that are long-lasting, bioaccumulative, and harmful to humans and wildlife. These pollutants are resistant to degradation and can persist in the environment for long periods of time, resulting in long-distance transport and bioaccumulation in the food chain.
PCBs (Polychlorinated Biphenyls): Once utilized in a variety of industrial applications such as electrical transformers and capacitors, PCBs are now prohibited in many countries due to their toxicity.
DDT (Dichlorodiphenyltrichloroethane): An pesticide that was widely used for agricultural and public health objectives in the past but is now restricted or banned due to its environmental and health effects.
Hence, the correct answer is PCBs and DDT. The correct option is (2) and (3).
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define potential difference as used in electricity
Answer:
This ability of charged particles to do work is called an electric potential.
Explanation:
When two negative charges are brought close to each other, they also repel. But when a positive and a negative charge are brought close together, they attract each other. When these two opposite charges are combined, they can be used to work. This is why we need a positive (+) and a negative (–) to light a bulb or run any electrical tool, equipment, mobile phone or home appliance.
Potential difference is the difference in the amount of energy that charge carriers have between two points in a circuit. ... The energy is transferred to the electrical components in a circuit when the charge carriers pass through them. We use a voltmeter to measure potential difference (or voltage).
What is the initial velocity (in m/s) of a car if it takes 10 seconds to travel a kilometer
while accelerating at 2 m/s??
Un péndulo de 4 m de longitud tiene una frecuencia de 5Hz. Calcular la longitud de otro péndulo que en el mismo lugar tiene una frecuencia de 4Hz
Conociendo la longitud y frecuencia de un péndulo, queremos encontrar la longitud de otro pendulo de tal forma que tenga otra frecuencia.
Veremos que la longitud del nuevo péndulo debe ser 6.25m
Sabemos que un péndulo de 4m de longitud tiene una frecuencia de 5Hz.
La frecuencia de un péndulo está dada por:
[tex]f = \frac{1}{2*\pi} *\frac{g}{l}[/tex]
Donde g es la aceleración gravitatoria y l es la longitud del péndulo, remplazando los datos que tenemos en esa ecuación obtenemos:
[tex]5 Hz = \frac{1}{2*3.14} *\sqrt{\frac{g}{4m} } \\\\(5Hz*2*3.14)^2*4m = g = 3,943.8 m/s^2[/tex]
Ahora debemos encontra la longitud de tal forma que la frecuencia sea 4Hz, entonces debemos resolver:
[tex]4Hz = \frac{1}{2*3.14} *\sqrt{ \frac{3943.8m/s^2}{l} }\\\\4hz*2*3.14 = \sqrt{ \frac{3943.8m/s^2}{l} }\\\\l =\frac{3943.8m/s^2}{ (4hz*2*3.14)^2} = 6.25m[/tex]
La longitud del nuevo péndulo deve ser 6.25m
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Using Newton's First Law, explain why, in a frictionless environment, a car that is under motion will not stop moving?
Answer:
According to Newton's first law of motion, an object maintains its state unless a force acts on it. Therefore, a moving car does not change its direction and keeps its speed unless a force acts on it.
A 12.0-g bullet is fired horizontally into a 112-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 149 N/m. The bullet becomes embedded in the block. If the bullet-block system compresses the spring by a maximum of 83.5 cm, what was the speed of the bullet at impact with the block
In which device is chemical energy transformed into electrical energy?
A.
battery
B.
hair dryer
C.
television
D.
hydroelectric plant
Answer:
A) Battery
Explanation:
A Battery because it holds lithium whatever stuff and we can use to power our electronics (Chemical -> electrical)
Hair dryers (electrical-> kinetic)
Television ( Electrical -> ???)
Hydroelectric plant ( Kinetic -> electrical)
Explain what is meant by the elastic limit of a spring.
Answer:
The elastic limit of a material is the furthest
point it can be stretched or deformed while
being able to return to its previous shape.
Explanation:
Once a material has gone past its elastic
limit, its deformation is said to be inelastic.
The higher the spring constant, the stiffer
the spring.
What force causes the passengers in a car to move forward when the car comes to a sudden stop?
Answer:
You and the car have inertia. If the car comes to a sudden stop, your body tends to keep moving forward. When the car starts moving again, your body tends to stay at rest. You move forward because the car seat exerts an unbalanced force on your body.
Explanation:
This is due to inertia. When the speeding bus stops suddenly, lower part of the body comes to rest while the upper part of the body tends to maintain uniform motion. Hence, the passenger's are thrown forward.
Atoms of which two elements could combine with atoms of carbon (C) to
form covalent bonds?
A. S
B. Na
C. N
D. K
E. Ca
Answer:
Correct answer is letter E.Ca
can anyone heelp me pls pls
Answer:
Lotion : semisolid
Suspension : liquid
capsule : solid
Explanation:
What force is required to accelerate a 1000-kilogram car at 6 m/s??
Answer:
Hence, Force (F) is 4000 Newtons.
Explanation:
ɢɪᴠᴇɴ :-
Mass (m) = 1000 kg
Acceleration (a) = 4 m/s²
ᴛᴏ Find:-
Force (F)
solution :-
We know that,
Force = mass × acceleration
➮ F = ma
➮ F = 1000 × 4
➮ F = 4000 N
Hence,
Force (F) is 4000 Newtons
(Hope this helps can I pls have brainlist (crown)☺️)
can anyone heelp me pls pls
Answer: Liquid - Lotion
Suspension - Semisolid
Capsule - Solid
Explanation:
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A car accelerates at 4 m/s/s from rest. What is the car's velocity after it travels 20 m?
Which term describes energy stored in the bonds between atoms?
A. Nuclear energy
B. Chemical energy
O C. Thermal energy
D. Sound energy
Answer:
B. Chemical energy
Explanation:
chemical energy is the energy stored in the bonds between atoms
Verificar
El gráfico de la velocidad de una bola que rueda por un canal se muestra en la
figura:
a) La velocidad de la bola luego de 5 s.
0.6m/s
b) La distancia recorrida en el intervalo t : (0-5) s
1.5m
c) La distancia recorrida en el intervalo t: (5-10) s
3m
d) La aceleración de la bola en el intervalo t: (10-12) s.
-0.4m/s^2
e) La distancia total recorrida.
6.9m
f) La rapidez media de la bola
0.58m/s
El análisis de un grafico de velocidad versus tiempo permite encontrar los resultados para las preguntas son:
a) La velocidad es v= 0,6 m/s
b) La distancia recorrida dₐ = 1,5 m
c) La distancia recorrida entre t= 5 y 10 s es [tex]d_b[/tex] = 3,0 m
d) La aceleración a = -0,4 m/s²
e) La distancia total recorrida es [tex]d_{total}[/tex] = 5,3 m
f) La velocidad media es [tex]v_{media}[/tex] = 0,44 m/s
La cinemática estudia el movimiento de los cuerpos, buscando relaciones entre la posición, la velocidad y la aceleración de los cuerpos.
La velocidad es definida como el cambio de la posición en función del tiempo y la aceleración es el cambio de la velocidad en el intervalo de tiempo.
.[tex]v= \frac{\Delta x}{t} \\a = \frac{\Delta v}{t}[/tex]
Donde v y a son la velocidad y aceleración, respectivamente, t es el tiempo y Δx y Δv son la variación de la posición y la velocidad, respectivamente.
En el adjunto muestran un grafico de la velocidad en función del tiempo, donde del área bajo la curva obtenemos la distancia recorrida y la pendiente corresponde a la aceleración del cuerpo.
Respondamos las preguntas:
a) La velocidad de la bola a los 5 s.
Como es un grafico de velocidad versus tiempo, la velocidad puede ser leída directamente, en el grafico tenemos un valor de
v= 0,6 m/s
b) La distancia recorrida corresponde al área bajo la curva.
[tex]d_a = \frac{v_f - v_o}{2} t \\d_a = \frac{0.6-0}{ 2}\ 5[/tex]
d = 1,5 m
c) La distancia en el intervalo de 5 a 10 s.
En este intervalo la velocidad es constante, el área es
[tex]d_b = v \Delta t\\d_b = 0.6 \ 5\\[/tex]
d = 3 m
d) La aceleración en el intervalo 10 a 12 s.
La aceleracion es la pendiente del grafico
a = [tex]\frac{\Delta v}{\Delta t}[/tex]
a = [tex]\frac{-0.2 - 0.6}{12-10}[/tex]
a = -0,4 m/s²
El signo negativo indica que la aceleración se opone a la velocidad del cuerpo.
e) La distancia total recorrida
[tex]d_{total} = d_a + d_b + d_c[/tex]
dₐ = 1,5 m
[tex]d_b[/tex] = 3,0 m
Busquemos la distancia en el ultimo intervalo
[tex]d_c = \frac{0.6 + 0.2}{2} ( 12-10)[/tex]
[tex]d_c[/tex] = 0,8 m
Substituimos
[tex]d_{total}[/tex] = 1,5 + 3,0 + 0,8
[tex]d_{total}[/tex] = 5,3 m
f) La rapidez de la bola
La rapidez prmedio es la relación entre la distancia recorrida en el tiempo.
[tex]v_{avg} = \frac{\Delta x}{\Delta t }[/tex]
[tex]v_{avg} = \frac{5.3}{12}[/tex]
[tex]v_{avg}[/tex] =0,44 m/s
En conclusión usando el análisis de un grafico de velocidad versus tiempo podemos encontrar los resultados para las preguntas son:
a) La velocidad es v= 0,6 m/s
b) La distancia recorrida da = 1,5 m
c) La distancia recorrida entre t= 5 y 10 s es db = 3,0 m
d) La aceleración a = -0,4 m/s²
e) La distancia total recorrida es [tex]d_{total}[/tex] = 5,3 m
f) La velocidad media es [tex]v_{avg}[/tex] = 0,44 m/s
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2. Calculate; The acceleration of any object due to Earth's gravity is -9.81 m/s. For every
second an object falls, its velocity changes by 9.81 meters per second. For several different
times on the table, multiply the time by the acceleration
A. What do you notice:
I
As the time of motion increases, the velocity of the object increases downwards.
The given parameters;
acceleration due to gravity, g = -9.81 m/s²velocity of the object, v₀ = 9.8 m/sThe final velocity of the object at different time is calculated as follows;
when the time = 1 second;
v = v₀ - gt
v = 9.8 - 9.8(1)
v = 0
when the time = 2 second;
v = v₀ - gt
v = 9.8 - 9.8(2)
v = -9.8 m/s
when the time = 3 second;
v = v₀ - gt
v = 9.8 - 9.8(3)
v = -19.6 m/s
Thus, we can conclude that as the time of motion increases, the velocity of the object increases downwards.
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A frictionless pendulum with a mass of 0.4 kg and a length of 2.1 m starts at point A, at an angle 0 of 60°. As it swings downward, it passes through point B, which is 30 degrees from equilibrium. What is the kinetic energy of the pendulum at point B?
A) 3.9 J
B) 3.0 J
C) 1.1 J
D) 4.1 J
The conservation of mechanical energy allows finding the result for the speed of the pendulum when it is at 30º is:
The speed is: 3.88 m / s
The conservation of mechanical energy is a theorem of greater importance in physics and ordinary life, it states that if there is no friction force the total mechanistic energy remains constant at all points.
Mechanical energy is the sum of kinetic energy plus all potential energies. In the attachment we see a diagram of the pendulum's movement at the two points of interest.
They indicate that the pendulum is released from an initial angle of θ₁ = 60º, let's find the mechanical energy at that point.
Em₀ = U = m g h
Where the height is measured from the lowest point of the movement.
h = L - L cos tea1 = L (1 cos tea1)
The second point of interest occurs for θ₂ = 30º.
At this point part of the energy is indica and part gravitational potential.
[tex]Em_f[/tex] = K + U₂
[tex]Em_f[/tex] = ½ m v² + m g h ’
There is no friction in the system, therefore mechanical energy is conserved.
Em₀ = Em₀_f
mg L (1 - cos θ₁) = ½ m v² + m g L (1 - cos θ₂)
v² = 2g L (cos θ₂ - cos θ₁)
Let's calculate.
v² = 2 9.8 2.1 (cos 30 - cos 60)
v² = 41.16 0.366
v = 3.88 m / s
In conclusion using the conservation of mechanical energy we can find the result for the speed of the pendulum when it is at 30º is:
The speed is: 3.88 m / s
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Answer:
3.0 J
Explanation:
Just took the test
Um cubo fechado com 1 m3 de um líquido (d=0,8; =21 000 kgf/cm2
) é submetido a um aumento de pressão de
20107 N/m2
. Calcule, no Sistema Internacional, as seguintes grandezas:
a) massa final;
b) peso final;
c) volume final;
d) massa volúmica final;
e) peso volúmico final.
Answer:
a. massa final
Explanation:
eu escolhi isso porque essa é a resposta espero que ajude você pode me dar uma ideia?
Jonathan wants to separate stones, insects and other unwanted materials in his mixture of grains and corn. What technique of separating mixture is appropriate
A. Winnowing
B. physical manipulation
C. Filtering
D. Magnetism
Answer:
What is B physical manipulation
Explanation:
Physical manipulation means fertilizers that are manufactured, blended, or mixed, or animal manures or compost that have been changed from their initial physical state by manipulations such as drying, cooking, chopping, grinding, shredding, ashing, or pelleting.
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In a game of tug of war, team one pulls to the right with a force of 500 newtons and team two pulls to the left with a force of 600 newtons. What is the net force?
Answer:
Explanation:
There is no set way to do this. All you have to do is define left and right. Left will be minus and right will be the opposite --- plus.
That is completely arbitrary. It could be the other way around. It does not matter.
Left is minus so: - 600 N is the force going left.
Right plus so: + 500 N
Now just add.
Net Force = +500 - 600
Net Force = - 100 N
So the Net Force is - 100 N going to the left.
Ex 2) A cannon ball is shot straight up into the air with an initial velocity of 25 m/s[Up).
What is the maximum height of the cannonball?
Explanation:
S=(V^2-U^2)/2a a=g (gravity) a=10
=(0^2-25^2/2*(-10)
=625/20
=31.25m
CAN SOMEBODY PLEASE HELP ME?!?!?!??!??!?!?!?!
Answer:
B. The force of gravity that acts on the kitten
Explanation:
Starting at 9a.m., you ride your hover board for 3hrs at an average speed of 6 mph. Out of breath, you stop for tea from noon until 2p.m. What is your average speed over the interval from 9a.m. to 2p.m.?