A concave mirror has a radius of curvature of 0.60 meter.
When an object is placed 0.40 meter from the reflecting
surface, the image distance will be
0.10 m
0.20 m
0.83 m
o 1.2 m
A small object begins a free-fall from a height of =81.5 m at 0=0 s . After τ=2.20 s , a second small object is launched vertically up from the ground with an initial velocity of 0=40.0 m/s . At what height from the ground will the two objects first meet?
Answer:
33.23 m
Explanation:
At the point where both objects will meet, the vertical height will be equal.
From the equations of motion, the vertical height of the body falling at any time is given as
(y - y₀) = ut + ½gt²
y = vertical height at any time T
y₀ = initial height of the object = 81.5 m
u = initial velocity = 0 m/s (body was dropped)
g = -9.8 m/s²
(y - 81.5) = 0 - 4.9T²
y = 81.5 - 4.9T² (eqn 1)
For an object thrown up, the vertical height of the body at any time, t, is given as
(y - y₀) = ut + ½gt²
y = vertical height of the object at any time t
y₀ = initial height of the object = 0 m
u = initial velocity = 40 m/s
g = -9.8 m/s²
y = 40t - 4.9t² (eqn 2)
At the point where the two objects meet, we equate eqn 1 and eqn 2
y = y
81.5 - 4.9T² = 40t - 4.9t²
But T = (t + 2.2) (Since object 2 was dropped 2.2 s after object 1)
81.5 - 4.9(t + 2.2)² = 40t - 4.9t²
81.5 - 4.9(t² + 4.4t + 4.84) = 40t - 4.9t²
81.5 - 4.9t² - 21.56t - 23.716 = 40t - 4.9t²
81.5 - 21.56t - 23.716 - 40t = 0
57.784 = 61.56t
t = (57.784/61.56) = 0.93866 = 0.94 s
Therefore, the vertical height at t = 0.93866 s is
y = (40×0.93866) - 4.9(0.93866²) = 33.23 m
Hope this Helps!!!
A car with a crashtest dummy inside travels at 40.23 m/s (90 mph) toward a stone wall during a crash test. When it strikes the wall, the car takes 0.70 s to stop. Calculate the deceleration of the car.
Answer:
The answer is [tex]-57.47m/s^{2}[/tex]Explanation:
In the question we are to solve for the deceleration of the car on impact.Given data
[tex]speed= 40.23m/s\\[/tex]
[tex]time[/tex] =[tex]0.70second[/tex]
To determine the deceleration we apply,
[tex]acceleration = \frac{speed}{time} \\\\acceleration= \frac{40.23}{0.7}[/tex]
[tex]acceleration = -57.47m/s^{2}[/tex]
Which statement below best describes the relationship between the voltage, resistance, and current?
Group of answer choices
A.) As voltage increases, current increases and resistance stays the same
B.) As voltage decreases, current and resistance stay the same
C.) As voltage decreases, current and resistance both increase
D.) As voltage increases, current and resistance both decrease
Answer:
As voltage increases, current increases and resistance stays the same .
Explanation:
Ohm's law gives the relationship between the voltage, resistance, and current. The mathematical form of Ohm's law is given by :
[tex]V\propto I\\\\V=IR[/tex]
R is resistance
I is current
V is voltage
So, as voltage increases, current increases and resistance stays the same. The correct option is (A).
You are pushing a box up a ramp with 70 N of force. If the ramp is made steeper and shorter, what needs to happen to the box for it to continue moving?
Answer:
A larger force than 70 N will be required for the box to continue moving
Explanation:
A ramp is an inclined plane surface that is tilted to form a slope on its opposite sides
A ramp provides mechanical advantage or force amplification, by allowing less force to lift heavier load from having to move through a longer distance to reach a particular elevation when the slope of the ramp is gentle
Therefore, when the slope is steeper, and shorter, more force than 70 N will be required for the box to continue moving.
Answer:
your force needs to increase to more than 70 N
Explanation:
plato
Un tren de pasajeros viaja a razon de 36km/hrs al ingresar a un tunel de 200m de longitud demora 50seg en salir de el .¿cuanto es la longitud del tren?
Answer:
[tex]\Delta L = 300\,m[/tex]
Explanation:
La longitud del tren se deriva de la siguiente fórmula (The length of the train is derived from the following formula):
[tex]\Delta L + 200\,m = v\cdot \Delta t[/tex]
[tex]\Delta L = \left(36\,\frac{km}{h} \right)\cdot \left(1000\,\frac{m}{km} \right)\cdot \left(\frac{1}{3600}\,\frac{h}{s} \right)\cdot (50\,s) - 200\,m[/tex]
La longitud del tren es (The length of the train is):
[tex]\Delta L = 300\,m[/tex]
The RMS potential difference of an AC household outlet is 117 V. a) What is the maximum potential difference across a lamp connected to the outlet? b) If the RMS current through the lamp is 5.5 A, what is the lam
Answer:
a. 165.5 V
b. 7.78 A
Explanation:
Here is the complete question
The RMS potential difference of an AC household outlet is 117 V. a) What is the maximum potential difference across a lamp connected to the outlet? b) If the RMS current through the lamp is 5.5 A, what is the maximun current through the lamp.
Solution
a. The maximum potential difference across the lamp V₀ = √2V₁ where V₁ = rms value of potential difference = 117 V
V₀ = √2V₁ = √2 × 117 V = 165.5 V
b. The maximum current through the lamp I₀ = √2I₁ where I₁ = rms value of current = 5.5 A
V₀ = √2V₁ = √2 × 5.5 A = 7.78 A
Se lanza desde el piso una piedra con velocidad vertical de +42 m/s. El punto de referencia se encuentra en el piso. Calcular: a). Escribir la ecuación de posición y la ecuación de la velocidad. b). Calcular en que instante su velocidad es nula. c). Calcular la máxima altura que llego. (Considerar la aceleración de la gravedad: a=9.81m/s2).
Answer:
a) y = 42 t - 4,905 t² , v = 42 - 9.81 t, b) t = 4.281 s , c) y = 89.9 m
Explanation:
This problem is an example of vertical launch
a) the expression for the position is
y = v₀ t - ½ g t²
we substitute
y = 42 t - 4,905 t²
the expression for speed is
v = v₀ - gt
v = 42 - 9.81 t
b) the speed is null when v = 0
v₀ = gt
t = v₀ / g
t = 42 / 9.81
t = 4.281 s
c) for the maximum height we can use the expression
v² = v₀² - 2gy
at maximum height v = 0
y = v₀² / 2g
let's calculate
y = 42 2/2 9.81
y = 89.9 m
The speed of light in a material is 0.50
c. what is the critical angle of a light ray at the interface between the material and a vacuum?
Answer:
Explanation:
This problem indicates that the speed of light in a material medium is 0.5 10⁸ m / s, they ask to find the critical angle between the material and the vacuum
Let's find the refractive index of the material
n = c / v
n = 3 10⁸ / 0.5 10⁸
n = 6
When the material passes from one medium to another, it must comply with the law of refraction
n₁ sin θ = n₂ sin θ₂
for the angle criticize the angles tea2 = 90
tea = sin⁻¹n₂/ n₁
The vacuum replacement index is n₂ = 1
tea = sin⁻¹ (1/6)
tea = 9.59º
Answer:
30 degrees
Explanation: First, what is the critical angle? Critical angle is the angle from the normal, at which light enters another medium, which causes the reflected light to reflect at an angle of 90 degrees.
Using Snell's Law:
critical angle = sin^-1(n2/n1)
n2 = c/v. In a vacuum this = 1
n1 = c/.5c = 2
critical angle = sin^-1(1/2)=30 degrees
Problem
When a piece of aluminum is
placed in a 25 ml
graduated
cylinder that contains 10.5mL of water, the water level rises to 13.5m. What is the mass of
the aluminum?
A 0.10 newton spring toy with a spring constant of 160 newtons per meter is compressed 0.05 meter before it is launched. When released the spring toy pops up and reaches a maximum height of 1.5 meters.
1) How much elastic potential energy is initially stored in the spring?
2)How much internal energy is produced as the toy springs up to its maximum height?
Answer:
(1) V = 0.2 J (2) 0.05J
Explanation:
Solution
Given that:
K = 160 N/m
x = 0.05 m
Now,
(1) we solve for the initial potential energy stored
Thus,
V = 1/2 kx² = 0.5 * 160 * (0.05)²
Therefore V = 0.2 J
(2)Now, we solve for how much of the internal energy is produced as the toy springs up to its maximum height.
By using the energy conversion, we have the following
ΔV = mgh
=(0.1/9.8) * 9.8 * 1.5 = 0.15J
The internal energy = 0.2 -0.15
=0.05J
The space shuttle approaches earth at a speed of 2.89*10^4 km/h when it sends a radio signal to earth 1.00*10^5 km away. The radio signal will reach earth in ____ seconds
Answer:
3 secods later
Explanation:
Where is earth's magnetic north pole located?
Answer: it is located over Ellesmere Island, Canada
Explanation
it is now drifting away from North America and toward Siberia.
Answer:ellesmere island, Canada
You're sitting on a warm granite rock, enjoying the sunshine. You decide it's time to test the water. You take off your shoes and walk across the cool sand to the water. You wade into the water, enough to cover your feet. Brrr! The water is cold. You will have to wear a dry suit when you go diving.
a. Which item - the granite rock, the sand, or the water - has the highest specific heat? Which has the lowest specific heat?
b. Which item requires the least energy to increase its temperature? Explain your answer in terms of this item's specific heat.
c. If the granite rock on which you were sitting has a specific heat of 600 J/(kg°C), how much energy must be added to a 2-kilogram piece of it to increase its temperature from 20°C to 30°C? Show your work, including the equation you need to perform this calculation.
d. What is the second law of thermodynamics? Use this law to describe why your feet got cold, not hot, when you put them in the water.
Answer: seen below
Explanation:
a) Water has the highest specific heat capacity in this case while sand has the lowest specific heat capacity.
b) Sand absorb the least energy for it temperature change (increase or decrease). This means that their temperatures change more quickly due to it low specific heat capacity of 0.290J/g°C) at 25°C)
c) using the formula:
Q = m × cP × (final temperature -initial temperature)
where:
Q = heat
m = is the mass
cP = is the mass heat capacity,
T= is the temperature
Q = 2 kg × 600 J/(kg°C) × (30°C - 20°C)
Q = 12000 J
d) in simpler term, The second law of thermodynamics states that when energy changes from one form to another form, entropy The second law of thermodynamics says that when energy changes from one form to another form, or matter moves freely, entropy (which is a measure of the amount of energy in a physical system that cannot be used to do work) in a closed system increases. This is why your feet gets cold when you put them in the water.
PLEASE HELP WILL GIVE BRANLIEST, EXTRA POINTS!
Jailah needs a replacement for lithium for a science experiment. She tries silicon, but it does not work. Using what you know about patterns in the periodic table, which advice would you give Jailah?
A. Try a lanthanide series element.
B. Try a non-metal from the halogen group.
C. Try an element in the same group as lithium.
D. Try an element in the same period as lithium.
Answer:
C. Try an element in the same group as lithium.
Explanation:
Answer:
The answer is C.
Explanation:
I'm took the test on it
what should police remove to study the physical conditions of a gun homicide case?
the victims clothes
any valuables from the victim (wallet, jewelry)
the victims cell phone
the victims dentures, if they wear any
Answer:
Explanation:
the victims cell phone
¿Alguien me puede ayudar? Problema: Un niño le pide gastada a su papá y éste le contesta que le dará los $120 que tiene en su bolsillo siempre y cuando conteste cuántas monedas de a $5 y de a $2 tiene en él si en total hay 33. ¿Qué debe contestar el niño si quiere los $120?
Answer: there are 15 coins of $2 and 18 coins of $5
Explanation:
I will answer in English.
X is the number of $5 coins.
Y is the number of $2 coins.
We have the system of equations:
Y + X = 33
Y*2 + X*5 = 120
first, we must isolate one of the variables in one of the equations and then replace it in the other equation, let's isolate Y in the first equation:
Y = 33 - X.
Then we can replace it in the other equation:
(33 - X)*2 + X*5 = 120
66 - X*2 + X*5 = 120
X*3 = 54
X = 54/3 = 18
and using the equation for Y.
Y = 33 - X = 33 - 18 = 15
So there are 15 coins of $2 and 18 coins of $5
Question 2
A wave with a frequency of 10 Hz and a wavelength of 4 m would have what speed?
m/s
Answer:
speed = 40 m/s
Explanation:
speed = frequency x wavelength
speed = 10 Hz x 4 m
speed = 40 m/s
If a 0.5 kg ball is thrown up with 250 J of kinetic energy, how high will it go?
(HINT: At the ball's highest point it has stopped.)
KE = 1/2mv2
G = 9.8 m/s2
Answer:
51.02m
Explanation:
KE = 1/2mv2
Where k.e = 250J
mass = 0.5 kg
g = 9.8 m/s2
250= 1/2×0.5×v^2
250= 0.5×0.5×v^2
250= 0.25v^2
v^2 = 250/0.25
v^2 = 1000
v =√1000
v = 31.62m/s
v^2= u^2-2gh........... (1)
Since the object will stop at it highest point, hence it final velocity there will be zero and since it is moving up against the gravity g= -9.8m/s^2. That was why the formula in equation 1 has a negative sign
From h = u^2/2g
Where v = 31.62m/s
g = 9.8m/s^2
H = (31.62m/s)^2/9.8×2
H= 1000/19.6
= 51.02m
Hence the height of it travelling will be
51.02m
El tiempo de reacción de un conductor de automóvil es 0,75s. Si el automóvil puede experimentar una desaceleracion de 4m/s^2. Calcular la distancia recorrida hasta detenerse una vez recibida la señal, cuando su velocidad era 10m/s
Answer:
x_total = 20m
Explanation:
This is an exercise in kinematics, we will look for the distance it travels during the reaction time, where there is no braking, and then the distance during the deceleration.
Distance traveled during response time
v = x₁ / t
x₁ = v t
let's calculate
x₁ = 10 0.75
x₁ = 7.5 m
Now we calculate the distance during braking, the final speed is zero (v = 0)
v² = v₀² - 2 a x₂
x₂ = v₀² / 2 a
let's calculate
x₂ = 10² / (2 4)
x₂ = 12.5m
the total stopping distance is
x_total = x₁ + x₂
X_total = 7.5 + 12.5
x_total = 20m
You accidentally drop a book down a stairwell. Assuming no air resistance,
how fast will the book be moving after 0.75 seconds?
Answer:
if we drop it and not throw it then
after 0.75 how fast the book is falling is given by its velocity as
v= at
= 9.8 × 0.75
=7.35 m/s
17.
What type of energy wave is highest in energy? (3 points)
Radio wave
Microwave
Visible light
Gamma wave
Answer:
gamma waves
Explanation:
gamma rays" from lightning discharges at 10 to 20 MeV, and known to be produced by the bremsstrahlung mechanism. Another example is gamma-ray bursts, now known to be produced from processes too powerful to involve simple collections of atoms undergoing radioactive decay.
How long will it take you to drive the 256 miles to get to the Mackinac Island Ferry if you average 70 mi/hr? If you leave at 3:00, what time will you get there? *Using speed formula
Answer:
If the speed is 70 mile/hour, the time to drive the 256 miles is:
T = 256/70 = 3.66 hours = 3 hours and 39.6 minutes
If you leave at 3:00, then at 6 hours and 39.6 minutes, you will get there.
Hope this helps!
:)
what is electrostatic force all about?
Explanation:
the electrostatic force is also known as the coulomb force or coulomb interaction. it's the attractive or repulsive force between two electrically charged object. like charges repel each other while unlike charges attract each other. coulomb's law is used to calculate the strength of the force between two charger .
Why can chemical energy and nuclear energy be considered a potential energy
Answer:
because it is due the Intrecation between sub atomic particles
If a car accelerates uniformly from rest to 15 meters
per second over a distance of 100 meters, the magnitude of the car’s acceleration is
Answer:
1.125 m/s²
Explanation:
Applying Newton's equation of motion,
v² = u²+2as
Where v = final velocity, u = initial velocity, a = acceleration, s = distance.
Note: u = 0 m/s ( from rest)
make a the subject of the equation above.
a = v²/2s................ Equation 2
Given: v = 15 m/s². s = 100 m
Substitute into equation 2
a = 15²/(2×100)
a = 225/200
a = 1.125 m/s²
The magnitude of the car's acceleration is 1.125 m/s²
The calculation can be as follows;
u= 0
v= 15m/s
s= 100 meters
The formular is
v²= u² + 2as
15² = 0² + 2(a)(100)
225= 200a
a= 225/200
a= 1.125
Hence the initial velocity is 1.125 m/s²
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El piloto de un contenedor parte de la ciudad de Guatemala a las 8:00 AM hacia Puerto Barrios, Izabal, debiendo recorrer 310 km sobre la carretera hasta llegar a la entrada del puerto donde debe entregar el contenedor a las 12:00 del mediodía. Calcule la rapidez promedio a la que deberá conducir el piloto para poderlo entregar a tiempo. Si el piloto sabe de antemano que debe detenerse una hora para hacer cola en el Progreso, por la ampliación de la carretera, calcule cuál debería ser entonces la rapidez promedio a la que debe conducir. ¿Medite si será posible o razonable que un contenedor viaje por la carretera a esa rapidez? Si la distancia en línea recta desde la ciudad de Guatemala hasta Puerto Barrios es de 250 km. ¿Cuál es la longitud de la trayectoria del contenedor? ¿Cuál fue su desplazamiento?
What is a lunar month
Answer:
It's the duration between successive new moons. Also called a lunation or synodic month, it has a mean period of 29.53059 days (29 days 12 hours and 44 minutes).
How do air quality scientists ensure the air is cleaned? What steps do they take?
i really need help !!
Answer:
The generator will work only if the magnetic field associated with the turns of coil change.
here both magnet and coil are stationary with respect to each other so no electromagnetic induction would take place. so no indiced current will be produced.
the student has to introduce some mechanism either to rotate the coil or the magnet