A construction laborer holds a 20 kg sheet of wallboard 3 m above the floor for 4 seconds. During these 4 seconds how much power was expended on the wallboard
Answer:
zero
Explanation:
no distance has moved while holding the sheet...so no distance means no workdone..no workdone means no power...
Two hockey pucks with mass 0.1 kg slide across the ice and collide. Before
the collision, puck 1 is going 15 m/s to the east and puck 2 is going 12 m/s to
the west. After the collision, puck 2 is going 15 m/s to the east. What is the
velocity of puck 1?
Answer:
Puck 1 = 12 m/s
Explanation:
Conservation of energy
KE_1a + KE_2a = KE_1b + KE_2b
(1/2)(0.1kg)(15m/s)^2 + (1/2)(0.1kg)(12m/s)^2 = (1/2)(0.1kg)(V)^2 + (1/2)(0.1kg)(15m/s)^2
V = 12m/s
Answer:
12 m/s west
Explanation:
just did it
A boat is drifting to the right with a speed of 5.0 m/s when the driver turns on the motor. The motor runs for 6.0 seconds causing a constant leftward acceleration of magnitude 4.0 m/s squared. What is the displacement of the boat over the 6.0 second time interval?
Answer:
[tex]D= -0.42km[/tex]
Explanation:
From the question we are told that
Drifting right with speed 5.0m/s
The motor runs for 6.0 seconds
Leftward acceleration of magnitude 4.0 m/s squared
Generally the equation [tex]V=ut+1/2at^2[/tex] can be used here
[tex]V=ut+1/2at^2[/tex]
Mathematically solving with the newton equation above we have that
[tex]D=5*6 + \frac{1}{2} (-4)*6^2[/tex]
[tex]D=30-72[/tex]
[tex]D=-42m[/tex] [tex]or -0.42km[/tex]
Therefore having this the Displacement is [tex]D= -0.42km[/tex] leftward
Determine the absolute pressure on the bottom of a swimming pool 30.0 mm by 8.4 mm whose uniform depth is 1.9 mm .
Answer:
=101343.62N/m^2
Explanation:
absolute pressure on the bottom of a swimming pool= atmospheric pressure +( 2 ×ρ ×g)
( 2 ×ρ ×g)= guage pressure
atmospheric pressure= 101325pa
h= height= 1.9 mm = 1.9×10^-3m
ρ = density of water
= 1000kg/m^3
g= acceleration due to gravity= 9.8m/s^2
Then substitute, we have
absolute pressure on the bottom of a swimming pool= 101325+ [0.0019 ×1000 × 9.8)]
=101343.62N/m^2
Hence, the absolute pressure on the bottom of a swimming pool is =101343.62N/m^2
What 2 factors do you need in order to calculate speed?
Answer:
Distance and time.
Explanation:
Speed=Distance/time
The two factors which we need in order to calculate the speed of an object are the distance covered by the object and the time taken to cover that distance.
What is Speed?
Speed is the rate of change of position of an object in any direction. Speed is a scalar quantity as it has only magnitude and no direction. It is measured as the ratio of the distance covered by an object to the time taken in which the distance was covered by that object.
Speed has the dimension of distance covered by the time taken. Thus, the SI unit of speed is the combination of the basic units of distance and the basic unit of Time. Thus, the SI unit of speed is meter per second (m/s).
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Deshaun Watson launches a football at a speed of 24.7 ms and an angle of 33° above the horizontal How far down
the football field does the football land? What is the max height the football reaches during flight?
Show work
Answer:
9.23m
Explanation:
Max height = u²sin²theta/2g
u is the speed = 34.7m/s
theta is the angle of elevation = 33°
g is the acceleration due to gravity = 9.8m/s²
Substitute into the formula
Max height = 24.7²sin²33/2(9.8)
Max height = 610.09sin²33/2(9.8)
Max height = 610.09(0.29663)/19.6
Max height = 180.97/19.6
Max Height = 9.23m
Hence the max height the football reaches during flight is 9.23m
Use the graph and the table above to complete the table by estimating the amount of energy transferred near location B.
A.
1600 kilojoules
B.
300 kilojoules
C.
800 kilojoules
D.
400 kilojoules
E.
3200 kilojoules
Answer:
A. 1600 kilojoules
Explanation:
Looking at the graph, at 4 meters, we can guess the energy transferred would be around 1500 kilojoules. 1600 kilojoules is the closest to that value, so A would be the best choice.
A horizontal force of 90.7 N is applied to a 40.5 kg crate on a rough, level surface. If the crate accelerates at 1.08 m/s, what is the magnitude of the force of kinetic friction (in N) acting on the crate?
let's say you hypothetically ran over someone with your car, and they are now under your car in between the front wheels and the back wheels, right, and they're stuck as in can't breathe type stuck, right, do you keep driving so they can breathe or do you let them chill under your car?
just curious...
question: is this actually hypothetical?
Explanation:
also just leave the car there go get some McDonald's or sum and come back and if they're still breathing then go ahead and move the car .
Answer:
the same thing the last guy said
14. After finishing her homework, Sue climbs up a 5.00 m high flight of stairs to her bedroom
Find the magnitude of Sue's weight
and how much
work Sue does in climbing the stairs if she
has a mass of 50.0 kg? (4.90 x 2 N, 2450J)
Explanation:
Given parameters:
Height = 5m
Mass of Sue = 50kg
Unknown:
Magnitude of Sue's weight = ?
Work done by Sue = ?
Solution:
Weight is the vertical force exerted by a body in the presence of gravity.
Mathematically;
W = mg
m is the mass
g is the acceleration due to gravity = 9.8m/s²
Weight = 50 x 9.8 = 490N
Work done = Force x distance = weight x height
Work done = 490 x 5 = 2450J
A 47.5-g ball moves at 30.0 m/s. If its speed is measured to an accuracy of 0.20%, what is the minimum uncertainty in its position
Answer:
The minimum uncertainty in its position is 1.85 x 10⁻³² m.
Explanation:
Given;
mass of the ball, m = 47.5 g = 0.0475 kg
speed of the ball, v = 30 m/s
measuring accuracy of the speed, = 0.2% = 0.002
The uncertainty in measurement of momentum;
ΔP = mΔv
ΔP = (0.0475)(30 x 0.002)
ΔP = 2.85 x 10⁻³ kgm/s
The uncertainty in position is calculated as;
[tex]\delta x \geq \frac{h}{4\pi (\delta P)}[/tex]
where;
h is Planck's constant
[tex]\delta x \geq \frac{6.626 \ \times \ 10^{-34}}{4\pi (2.85 \ \times \ 10^{-3})} \\\\\delta x \geq 1.85 \ \times \ 10^{-32} \ m[/tex]
Thus, the minimum uncertainty in its position is 1.85 x 10⁻³² m.
A student is creating an electromagnet for an investigation. Which feature of the electromagnet will least influence the magnetic force?
A
the material of the core
B
the brand of the battery
С
the number of wire coils
D
the che of the power source
which of the following is not a mechanical form of energy?
a. Nuclear
b. Kinetic
c. Spring potential
d. Gravitational potential
Answer:
The answer is Spring Potential
Explanation:
Because all the others are a mechanical form of energy
If the angle between two forces increases, the magnitude of their resultant-
A Decreases
C. Remain unchanged
D. Decrease than decreases
Which type of telescope is best used to detect distant planets?
The least count of stopwatch is 0.2s.The time of 20 oscillations of a pendulum was measured to be 25s.Find the percentage error in the measurement of time
Answer:
0.8%
Explanation:
We are given;
Number of oscillations; n = 20
Time taken; t = 25 s
Formula for period of oscillation;
T = t/n = 25/20 = 1.25 s
We are told that the least count is 0.2 s. Thus, error is; ΔT = 0.2 s
percentage error in the measurement of time is given by;
(0.2/(20 × 1.25)) × 100% = 0.8%
A 4 kg bowling bowl is sitting on a table 1 meter off the ground. How much potential energy does it have?
Answer:
[tex]\huge\boxed{\sf P.E. = 39.2\ Joules}[/tex]
Explanation:
Given Data:
Mass = m = 4 kg
Acceleration due to gravity = g = 9.8 m/s²
Height = h = 1 m
Required:
Potential Energy = P.E. = ?
Formula:
P.E. = mgh
Solution:
P.E. = (4)(9.8)(1)
P.E. = 39.2 Joules
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807An inductor with an inductance of .5 henrys (H) is to be connected to a 60 Hz circuit. What will the inductive reactance (X L) be
Answer:
1885.2 ohms
Explanation:
Step one:
given data
L=5H
f=60Hz
Required
The inductive reactance of the inductor
Step two:
Applying the expression
XL= 2πfL
substitute
XL=2*3.142*60*5
XL=1885.2 ohms
An automobile which set the world record for acceleration increase speed from rest to 96 km/h in 3.07 seconds what distance traveled by the time the final speed was achieved
Answer:
41.02m
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 96km/hr
Time taken = 3.07s
Unknown:
Distance traveled by the time the final speed was achieved = ?
Solution:
To solve this problem, we first find the acceleration of the car;
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Now convert the the final velocity to m/s;
96km/hr to m/s;
1 km/hr = 0.278m/s
96km/hr = 96 x 0.278 = 26.7m/s
Now;
Acceleration = [tex]\frac{26.7 - 0}{3.07}[/tex] = 8.69m/s²
So;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
26.7² = 0² + 2 x 8.69 x s
712.89 = 17.38s
s = 41.02m
The metal wire is stretched so that its cross-section is still circular but its total length is now 10 meters. What is the resistance of the wire after stretching
Help! Help!
___ are a primary way to discourage drinking and driving.
A. High prices for alcohol
B. Scare tactics
C. Laws
Answer:
Laws
Explanation:
Laws are a primary way discourage drinking and driving
A primary way to discourage drinking and driving is Law.
What is drinking and driving?The person who takes in alcohol and then drives on the road. This is strictly prohibited.
Laws against the 'drinking and driving' will make people get scared of getting charged or sentenced to jail for some years. Lot of accidents have caused when there were no laws against the action.
Thus, Laws are a primary way to discourage drinking and driving.
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What type of telescope did Galileo use to observe Jupiter?
reflector telescope
refractor telescope
radio telescope
latter telescope
Answer:
a refractor telescope
Explanation:
Answer:
a. refractor telescope
( I will give a brainliest )
What must be changed, temperature or heat energy, during condensation?
Answer:
The answer is temperature lol
Explanation:
:)
Marvin the Martian needs to get back home. Marvin is 321,770 m from his home on Mars. He decides the quickest way to get home is to use his canon to fire himself into flight. He aims the the canon at an angle of 25 degrees. When the canon is fired Marvin the Martian is launched into flight at an initial velocity of 1250 m/s. The question is will his plan work
Answer:
y = 14238 m. the height of the rocket is much less than this distance therefore the plan will not work.
Explanation:
Let's analyze this exercise, so that the Martian's plan works, the vertical height of the body must be zero when it is more than half of the way to the planet Mars, this is so that Mars attracts it and can arrive.
Let's calculate the maximum height of the launch
[tex]v_{y} ^2 = v_{oy}^2 - 2 g y[/tex]
at the highest point [tex]v_{y}[/tex] = 0
y = v_{oy}² / 2g
y = (v₀ sin θ)² / 2g
let's calculate
y = (1250 sin 25)² /2 9.8
y = 14238 m
In the exercise, indicate that the distance to Mars is h = 321770 m, half of this distance is
h / 2 = 160885 m
therefore the height of the rocket is much less than this distance therefore the plan will not work.
The height reached is low, so it is not necessary to take into account the variation of g with height
Q2. You push a crate up a ramp with a force of 10 N. Despite your pushing, the crate slides down the ramp 4 m. How much work did you do
Answer:
40 J
Explanation:
From the question given above, the following data were obtained:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Work done is simply defined as the product of force and distance moved in the direction of the force. Mathematically, we can express the Workdone as:
Workdone = force × distance
Wd = F × s
With the above formula, we can obtain the workdone as follow:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Wd = F × s
Wd = 10 × 4
Wd = 40 J
Thus, 40 J of work was done.
1. A 75.0 kg man pushes on a 500,000kg wall for 250s but it does not move. How
much work does he do on the wall?
Answer:
0J
Explanation:
No work is being done on the wall by the man pushing on it.
Given parameters:
Mass of man = 75kg
Mass of wall = 500000kg
Time = 250s
Unknown:
Work done = ?
Solution:
Work done is the force applied on a body that moves it along a particular path.
For work to be done, distance must be move or displacement must occur.
Since the wall is not moving the distance is 0;
Work done = Force x distance
Since distance is 0m, work done is 0J
The work done on the wall by the man is 0 J.
To calculate the amount of work done by the man, we use the formula below.
Formula:
W = (ma)d............. Equation 1Where:
W = Work done on the wall by the manm = mass of the walla = acceleration of the walld = distance.from the question,
Given:
m = 500000 kga = 0 m/s² (not moving)d = 0 m.Substitute these values into equation 1
W = 500000(0)(0)W = 0 J.Hence, the work done on the wall by the man is 0 J.
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write the difference between convert and
Concave minores
The device shows the relative humidity at 22°C. What’s the water vapor density if the maximum water vapor in air at this temperature is 20 grams/cubic meter?
A device showing that at 22 degrees Celsius the relative humidity is 58%.
Answer:
The answer would be 11.6 g/m^3
Explanation:
Knowing that vapor's density at 100% humidity is 20g/m^3 we can calculate the answer using the following math:
0.58 * 20 = 11.6 grams per cubic meter
the units can also be written as g/m^3
The density of water vapor is 11.6 grams/cubic meter.
What is relative humidity?The quantity of atmospheric moisture that is present compared to the amount that would be there if the air were saturated is known as relative humidity, and it is stated as a percentage. Relative humidity depends on both moisture content and temperature because the latter quantity is temperature-dependent. The related temperature and dew point for the specified hour are used to calculate relative humidity. it is expresses as %.
Now given that the maximum water vapor in air at this temperature is 20 grams/cubic meter at 22°C, that is, density of vapor at 100% humidity is 20g/[tex]m^3[/tex] at 22°C.
And, The device showing that at 22 degrees Celsius the relative humidity is 58%
So, water vapor density at that moment is = 20g/[tex]m^3[/tex] × 58%
= 11.6 g/[tex]m^3[/tex] .
= 11.6 grams/cubic meter.
Hence, according to the measurement of device, the water vapor density is 11.6 grams/cubic meter.
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Define friction. Prove that tangent of angle of friction is equal to coefficient
of friction.
Answer:
Friction is the force that opposes movement between moving objects.
The angle at which one object starts to slip on the other is directly related to the coefficient. When the two objects are horizontal there is no frictional force. So, the coefficient of static friction is equal to the tangent of the angle at which the objects slide. A similar method can be used to measure μk.
Explanation:
Answer:
brainliest plsssssss
Explanation:
The resistance that one surface or object encounters when moving over another
What happens to most of the light waves that strike a clear pane of glass? O A. absorption B. diffraction O C. reflection O D. transmission
slight reflect but most goes through because glass is transparent
Most of the light waves that strike a clear pane of glass reflects. Details about reflection can be found below.
What is reflection?Refection in physics is the property of a propagated wave being thrown back from a surface such as a mirror.
Mirror is an example of an object that could be hit by an incumbent wave, however, most of the light waves that hit the mirror surface gets reflected back.
Therefore, most of the light waves that strike a clear pane of glass reflects.
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