Answer:
The First 8 Presidents
For this exercise, we're going to use a silly story made of silly sentences. The letters that represent the last names of these presidents are W, A, J, M, M, A, J, V. One silly sentence to help you remember this sequence is: Wilma and John made merry and just vanished
working memory.
sensory memory.
short-term memory.
long-term memory.
2 W' is the symbol of a) antimony b) gold c) polonium d) tungsten
Answer:
D. Tungsten
Explanation:
W - Wolfram
Find the time it takes for an object dropped from a building and reaches a final velocity of 20 m/s downward?
I need the formula
Answer:
Explanation:
v = at
t = v/a
t = 20 m/s / 9.8 m/s²
t = 2.0408163...
t = 2.0 s
A solar collector for a hot water system absorbs solar radiation at the rate of 660 W/m^2
. Its collecting area is 3.8m^2 . Cold water at 15degrees enters the collector. What volume of
water per minute at an output temperature of 60 degrees can this collector deliver?
This question involves the concepts of the law of conservation of energy and specific heat capacity.
This collector can deliver "7.96 x 10⁻⁴ m³/min" of water at an output temperature of 60°C.
According to the law of conservation of energy:
Solar Energy = Energy Required to raise the temperature of the water
Solar Power = Energy Required to raise the temperature of the water
[tex]IA=\frac{mC\Delta T}{t}\\\\\frac{m}{t}=\frac{IA}{C\Delta}[/tex]
where,
[tex]\frac{m}{t}[/tex] = mass flow rate = ?
I = solar radiation = 660 W/m²
A = Area = 3.8 m²
ΔT = change in temperature = 60°C - 15°C = 45°C
C = specific heat capacity = 4200 J/kg.°C
Therefore,
[tex]\frac{m}{t}=\frac{(660\ W/m^2)(3.8\ m^2)}{(4200\ J/kg.^oC)(45^oC)}\\\\\frac{m}{t}=(0.0133\ kg/s)(\frac{60\ s}{1\ min})\\\\\frac{m}{t}=0.796\ kg/min[/tex]
Now, the volume flow rate will be:
[tex]\frac{V}{t}=\frac{(\frac{m}{t})}{(density\ of\ water)}=\frac{(0.796\ kg/min)}{(1000\ kg/m^3)}\\\\\frac{V}{t}=7.96\ x\ 10^{-4}\ m^3/min[/tex]
Learn more about the law of conservation of energy here:
brainly.com/question/20971995?referrer=searchResults
The attached picture explains the law of conservation of energy.
An above ground swimming pool of 30 ft diameter and 5 ft depth is to be filled from a garden hose (smooth interior) of length 100 ft and diameter 5/8 inch. If the pressure at the faucet to which the hose is attached remains at 55 psi, how long will it take to fill the pool
This question involves the concepts of dynamic pressure, volume flow rate, and flow speed.
It will take "5.1 hours" to fill the pool.
First, we will use the formula for the dynamic pressure to find out the flow speed of water:
[tex]P=\frac{1}{2}\rho v^2\\\\v=\sqrt{\frac{2P}{\rho}}[/tex]
where,
v = flow speed = ?
P = Dynamic Pressure = 55 psi[tex](\frac{6894.76\ Pa}{1\ psi})[/tex] = 379212 Pa
[tex]\rho[/tex] = density of water = 1000 kg/m³
Therefore,
[tex]v=\sqrt{\frac{2(379212\ Pa)}{1000\ kg/m^3}}[/tex]
v = 27.54 m/s
Now, we will use the formula for volume flow rate of water coming from the hose to find out the time taken by the pool to be filled:
[tex]\frac{V}{t} = Av\\\\t =\frac{V}{Av}[/tex]
where,
t = time to fill the pool = ?
A = Area of the mouth of hose = [tex]\frac{\pi (0.015875\ m)^2}{4}[/tex] = 1.98 x 10⁻⁴ m²
V = Volume of the pool = (Area of pool)(depth of pool) = A(1.524 m)
V = [tex][\frac{\pi (9.144\ m)^2}{4}][1.524\ m][/tex] = 100.1 m³
Therefore,
[tex]t = \frac{(100.1\ m^3)}{(1.98\ x\ 10^{-4}\ m^2)(27.54\ m/s)}\\\\[/tex]
t = 18353.5 s = 305.9 min = 5.1 hours
Learn more about dynamic pressure here:
https://brainly.com/question/13155610?referrer=searchResults
What is the formula of [tex]\underline{force}[/tex]in physics?
The formula of force is F = ma.
Force: This can be defined as the product of mass and acceleration. The S.I unit of force is Newton (N). Force is a vector quantity
Types of force
Friction forcePushPullUpthrustTensional force.
⇒ The formula of force is
F = ma................ Equation 1
⇒ Where:
F = forcem = mass of the bodya = accelerationHence, the formula of force is F = ma.
Learn more about force here: https://brainly.com/question/13370981
Before looking at the formula, Lets understand what is force?
Force:- Force can be defined as the cause of motion of an object. Force can change the shape, direction and velocity of an object.It's SI unit is NewtonThe formula used to find force is:
[tex] \sf \nrightarrow \: F=m×a[/tex]
Where,
F is forceM is mass of the bodyA is accelerationEquation in words:- Force applied on an object is directly proportional or equal to the product of the mass of object and the acceleration of object.
What is the angle of incidence when incident ray is reflected backwards along the same path
Answer:
The angle of incidence = The angle of reflection
Explanation:
For instance, the formula is <i = <r which means if the surface is smooth then the reflacted anglw will be equal according to the normal (dotted 90°) line.
Upon being reflected backwards the angle of incidence is simply the same, except from the other side
Wrte down the effect of humidity and temperature in the speed of sound....
Explanation:
the speed of sound is affected by temperature and humidity
Please help me as quick as possible!!!!!!! Please, please please!!!!!!
Answer:
23
Explanation:
3x-4
Assume that two cars have the same kinetic energy, but that the red car has twice the speed of the blue car. We then know that the red car has ____ mass as the blue car.
Answer:
equal
Explanation:
Peregrine falcons, which can dive at 200 mph (90 m/s), grab prey birds from the air. The impact usually kills the prey. Suppose a 480 g falcon diving at 75 m/s strikes a 240 g pigeon, grabbing it in her talons. We can assume that the slow-flying pigeon is stationary. The collision between the birds lasts 15 ms.
Answer:
What is the average force of collision?
Explanation:
The velocity of the combined mass after impact is found by conservation of momentum
0.480(75) + 0.240(0) = (0.480 + 0.240)v
v = 50 m/s
An impulse results in a change of momentum
FΔt = mΔv
F = mΔv/Δt
for the pigeon
F = 0.240(50 - 0)/0.015
F = 800 N
for the falcon
F = 0.480(50 - 75)/0.015
F = -800 N
The final speed(v) of the Peregrine falcons and pigeon is 50 m/s
The objective of this question is to determine the final speed(v) of the Peregrine falcons and pigeon
From the information given:
the mass of the falcon m_f = 480 gthe speed of the falcon v_f = 75 m/sthe mass of the pigeon m_p = 240 gthe collision time = 15 ms = 0.015 sAccording to the conservation of momentum, we can say that the totality of momentum before and after the collision is the same. As such;
[tex]\mathbf{m_fv_f = (m_f+m_p) v}[/tex]
[tex]\mathbf{480 g \times 75 m/s = (480 + 240) \ g \times v}[/tex]
[tex]\mathbf{v = \dfrac{480 g \times 75 m/s}{(480 + 240) \ g}}[/tex]
[tex]\mathbf{v = \dfrac{36000 \ m/s}{ 720}}[/tex]
v = 50 m/s
Learn more about conservation of momentum here:
https://brainly.com/question/18066930?referrer=searchResults
why does air pressure decrease with increasing altitude?
An airplane accelerates down a runway at 3.20 m/s2 for 32.8 s until is finally lifts off the ground. Determine the distance traveled before takeoff.
Answer:
The distance traveled before takeoff is 1720 m
Explanation:
Given:a = + 3.2 m/s²
t = 32.8 s
Vᵢ = 0 m/s
To Find:d = ?
Now,
d = Vᵢ × t + 0.5 × a × t²
d = (0 m/s) × (32.8 s) + 0.5 × (3.20 m/s²) × (32.8 s)²
d = 1720 m
Thus, The distance traveled before takeoff is 1720 m
-TheUnknownScientist 72
Can someone PLEASE help me??
E TRUE OR FALSE: Write the word TRUE if the statement is correct, and FALSE if it is not. (3 points each). Write your answer on a separate sheet of paper. 1. Most EM waves has the same speed. 2. EM waves travel at the speed of 4x108 m/s. 3. Electromagnetic waves are transverse waves consisting of changing electric fields and changing magnetic fields. 4. Electromagnetic waves transfer energy through a vacuum. 5. A wave is a disturbance that transfers energy .what the answer?
Answer:
TRUE
FALSE
TRUE
TRUE
TRUE
TRUE
Explanation:
1. Most EM waves has the same speed. True
2. EM waves travel at the speed of 4x108 m/s. False
3. Electromagnetic waves are transverse waves consisting of changing electric fields and changing magnetic fields. True
4. Electromagnetic waves transfer energy through a vacuum. True
5. A wave is a disturbance that transfers energy. True
A father (75 kg) was standing watching TV, minding his own business when one of his kids (20 kg) approached him at 2m/s heading at 0 degrees and jumped onto his back. Another kid (15 kg) approached him at 3m/s heading at 45 degrees to the first kid and also jumped on him at exactly the same time. Immediately after impact, in what direction did the group go (measured in degrees with respect to the first kid)
Answer:
Explanation:
Conservation of momentum
Let's say the first child was headed north
North momentum
75(0) + 20(2) + 15(3sin45) = (75 + 20 + 15)vn
vn = 0.6529 m/s
East momentum
75(0) + 20(0) + 15(3cos45) = (75 + 20 + 15)ve
ve = 0.28927 m/s
θ = arctan(0.28927/0.6529)
θ = 23.896...
θ = 24° east of north
Two airplanes taxi as they approach the terminal. Plane 1 taxies with a speed of 13 m/s due north. Plane 2 taxies with a speed of 8.5 m/s in a direction 20 ∘ north of west.
Part A
What is the magnitude of the velocity of plane 1 relative to plane 2?
Part B
What is the direction of the velocity of plane 1 relative to plane 2?
Part C
What are the magnitude of the velocity of plane 2 relative to plane 1?
Answer:
Explanation:
Plane 2 is moving north at
8.5sin20 = 2.9 m/s
Plane 2 is moving west at
8.5cos20 = 8.0 m/s
Part A
v = √((13 - 2.9)² + 8.0²) = 12.876... 13 m/s
Part B
θ = arctan((13 - 2.9) / 8.0) = 51.617... 52° N of E
Part C
13 m/s 52° S of W
relative velocity magnitude is independent of reference frame
A stomp rocket takes 3.1 seconds to reach its maximum height.
- What is its initial velocity? (Do not use units. If the answer is negative, please put a
negative sign in front of the answer.)
- What is its maximum height? (Do not use units. If the answer is negative, please put a
negative sign in front of the answer.)
Answer:
Explanation:
Ignoring air resistance the time to rise will equal the time to fall and initial velocity will be the same magnitude as final velocity just before impact.
v = at
v = 9.8(3.1)
v = 30.38
v = 30 m/s
max height can be found knowing the velocity is zero at the top of its flight.
v² = u² + 2as
s = (v² - u²) / 2a
s = (0.00² - 30.38²) / (2(-9.8))
s = 47.089
s = 47 m
A stomp rocket takes 3.1 seconds to reach its maximum height then the initial velocity is given as v = 30 m/s and maximum height is 47.089 m.
What is Velocity?Velocity is defined as rate of change of position with respect to time.
SI unit of velocity is m/sec. Velocity is a vector quantity.
Given that in the question time taken by rocket to reach maximum height is 3.1 sec. Ignoring air resistance the time to rise will equal the time to fall and initial velocity will be the same magnitude as final velocity just before impact.
v = at
v = 9.8(3.1)
v = 30.38
v = 30 m/s
Max height can be found knowing the velocity is zero at the top of its flight.
v² = u² + 2as
s = (v² - u²) / 2a
s = (0.00² - 30.38²) / (2(-9.8))
s = 47.089
s = 47 m
So, the initial velocity is given as v = 30 m/s and maximum height is 47.089 m.
To learn more about Velocity refer to the link:
brainly.com/question/18084516
#SPJ5
If you drop your keys from the tallest building in San Antonio, how fast will
they be falling after 3 seconds?
9.8 m/s
0 14,7 m/s
29.4 m/s
44,1 m/s
Hi there!
We can use the equation:
v = at, where in this instance:
v = velocity (m/s)
a = acceleration due to gravity (m/s²)
t = time (s)
g ≈ 9.8 m/s², so:
v = 9.8(3) = 29.4 m/s
Swim swim swim swim swim swim swim swim swim swim swim swim.
An object at rest on a flat, horizontal surface explodes into two fragments, one seven times as massive as the other. The heavier fragment slides 5.60 mm before stopping. How far does the lighter fragment slide
Answer:
M1 + M2 = 0 total momentum before explosion = momentum after explosion where M1 is the lighter fragment
M1 V1 + 7 M1 V2 = 0
V2 = -V1 / 7
The lighter fragment will slide 7 times as far - 39.2 mm because it must have 7 times as much velocity - assuming the distance slid is proportional to the original velocity
Just need the answer
Answer:
1. 1, 2, 4 all show some form of refraction as the bending of a light ray when passing from one media to another.
Explanation:
Number 4 is the most accurate as it also shows some light being reflected and the bending of the refracted light ray in the correct direction for going from a medium of low refractive index (air) into a higher refractive index material (crown glass)
A ball is thrown up into the air. When it gets to the very top,
what kind of energy does it have?
At the highest attitude, the velocity of the ball is 0 m/s, so the kinetic energy is 0 as well.
Hence the answer is potential energy because it doesn't depend on velocity .
PLEASE HELP!
A 2457 kg car moves with initial speed of 18 ms-?. It is stopped in 62 m by its brakes.
How much work is done by the brakes?
Answer:
Explanation:
The work of the brakes will equal the initial kinetic energy of the car
Fd = ½mv²
F = mv²/2d
F = 2457(18²) / (2(62))
F = 6,419.903...
F = 6.4 kN
Which item is not a solid-state component?
an integrated circuit
a vacuum tube
a diode
a transistor
Answer:
a vacuum tube is NOT a solid state component
Children in a tree house lift a small dog in a basket 3.85 m up to their house. If it takes 201 J of work to do this, what is the combined mass of the dog and basket
Answer:
Explanation:
The work will equal the increase in potential energy.
PE = mgh
m = PE/gh = W/gh = 201/(9.81(3.85)) = 5.32 kg
What state of matter is jelly?
Answer:
Hey mate.....
Explanation:
This is ur answer.....
SolidsJelly is a colloid where colloidal particles are solids which are dispersed in the liquid. Jelly is a fluid which can not be considered as a particular one kind of state. It is in the category of 'gel' which is a colloidal form.
Hope it helps!
Brainliest pls!
Follow me! ;)
How do humans obtain the carbon and energy they use in their bodies?
A. by breathing in carbon dioxide from the atmosphere
B. by consuming plants or other animals
C. by absorbing energy from sunlight
D. by absorbing carbon found in the soil
Answer:
B. . by consuming plants or other animals
How fast would a(n) 75 kg man need to run in order to have the same kinetic energy as an 8.0 g bullet fired at 390 m/s
Answer:
Explanation:
½(75)v² = ½(0.008)390²
v² = (0.008)390²/75
v² = 16.224
v = 4.027...
v = 4.0 m/s
A circular coil having 60 turns has a radius of 75 mm. What current must exist in the coil
to produce a magnetic field of 300 μT at the center of the coil?
Answer:
Explanation:
Step 1 of 4
CONCEPT:
The mathematical expression for magnetic field B at center of a coil:
Here, is the current in the coil, N is the number of turns of the coil, is the permeability of the free space and is radius of the coil.
Rearrange above equation for current in the coil.
What is speed of sound in air?
Answer:
speed of sound, speed at which sound waves propagate through different materials. In particular, for dry air at a temperature of 0 °C (32 °F), the modern value for the speed of sound is 331.29 metres (1,086.9 feet) per second