Answer:
–625 J
Explanation:
So, we got this formula for the work
W=mgd(Cosθ)
but remember when it's liftin somethin, its work gon be against the work of gravity, so
Cos180°= –1
W=500×1.25×(–1)
W= –625 J
A boat of mass 225 kg drifts along a river at a speed of 21 m/s to the west.
What impulse is required to decrease the speed of the boat to 15 m/s to the
west?
A. 3375 kg•m/s west
B. 1350 kg•m/s east
C. 1350 kg•m/s west
D. 3375 kg•m/s east
Explanation:
I=MV
=225×(15- 21)
=225×-5
Answer:
B. 1350 kg•m/s east
Explanation:
........
define acceleration what it's formula
Answer:
The definition of acceleration is a change in the rate of motion, speed or action.
hope it helps.stay safe healthy and happy..Acceleration is the rate of change of velocity.
[tex]acceleration = \frac{(final \: velocity - initial \: velocity)}{time} \\ or \\ a = \frac{(v - u)}{t} \\ \\ The \: S.I. \: unit \: of \: acceleration \: is \: \frac{m}{ {s}^{2} } \: or \: m {s}^{ - 2} [/tex].
My last year's notes on acceleration is attached. Hope it helps you!!
A 6 m/s vector pointing North is added to a 2 m/s vector pointing East. What are the magnitude and direction of the resultant?
Answer:
A + B = C Ax = 2 Ay = 0 Bx = 0 By = 6
Ax + Bx = Cx = 2
Ay + By = Cy = 6
C = (2^2 + 6^2)^1/2 = 6.32
Tan Cy / Cx = 6 / 2 = 3
Cy at 71.6 deg
Using atomic weight crystal structure and atomic radius data tabulated inside the front cover compute the theoritical densities of alminuim ,nikel......
Question
Using atomic weight, crystal structure, and atomic radius data tabulated inside the front cover of thebook, compute the theoretical densities of aluminum (Al), nickel (Ni), magnesium (Mg), and tungsten (W), and thencompare these values with the measured densities listed in this same table. The c/a ratio for magnesium is 1.624.
Explanation:
How does the construction of dams positively affect natural resources?
by providing water for irrigation and restoring trees to areas where forests once existed
by creating reservoirs, preventing flooding, and renewing destroyed ecosystems
by preventing flooding, creating reservoirs, and providing water for irrigation
by renewing destroyed ecosystems and restoring trees to areas where forest once existed
Other person is incorrect, I did the test on edg.
Answer:
A. by providing water for irrigation and restoring trees to areas where forests once existed
The construction of dams positively affect natural resources by providing water for irrigation.
What is natural resources?Natural resources serves as materials thst is found in nature which are used by humans. These natural substances are soil, water.
Therefore, building of dams can help irrigation by using water which is a natural resources.
Learn more about natural resources at;
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What is the correct equation for the y axis of object B?
Answer:
[tex]N_B-W_B = 0[/tex]
Explanation:
There are two forces acting on object B. If we consider the law of equilibrium, then the two forces must be equal in magnitude, for the object to remain in equilibrium position:
[tex]N_B = W_B\\\\N_B-W_B = 0[/tex]
Therefore, the correct answer of the given question, from the given choices, is:
[tex]N_B-W_B = 0[/tex]
A boy is moving a stone in a horizontal circle by mean of a thread attached to ut. The length if the threads us 1 m and the weight of the stone is 0.02 kg . The maximum tension of the thread can withstand us 1 ×10 ^-4 N. The boy is gradually increasing the speed if rotation. At what speed if the stone does the thread break ?
Answer:
Explanation:
This is a centripetal force problem where tension supplies the centripetal force needed to keep the stone moving in a circular manner. That formula for that is
[tex]F_c=T=\frac{mv^2}{r}[/tex] and filling in what we know:
[tex]1*10^{-4}=\frac{.02v^2}{1}[/tex] and solve that for v:
[tex]v=\sqrt{\frac{1*10^{-4}}{.02} }[/tex] which gives us a velocity of .07 m/s. Anything greater than this will break the string.
what is the value of acceleration due to gravity at the equatorial region of the earth
Answer:
9.78 m/s^2
Explanation:
Acceleration due to gravity at equator is 9.78m/s^2
a ball is launched from the ground with a horizontal speed of 30 m/s and a vertical speed of 30 m/s. what is the balls overall speed at the top of its trajectory?
Answer:
30m/ s
Explanation:
this is an example of a projectile, where the path traced by the ball will be a downward parabola.
one must know that the vertical velocity of an object having projectile motion is zero at the top of its trajectory and that the horizontal velocity remains constant throughout.
this means, at the top of the trajectory the ball's overall speed will be equal to its horizontal velocity.
and horizontal velocity is given 30 m/s
hence, overall speed of the ball = 30m/ s
When an apple falls towards the earth, the earth moves up to meet the apple . Is this true ? If yes . Why is the earth's motion not noticeable.
What do you think Jose’s grandmother meant by saying that the bread was too dense? What other things can you think of that are “dense”?
Answer:
What I think that Jose's grandmother meant by saying that the bread was too dense is that she thinks the bread is too heavy or it can even mean to be too compacted in substance. The matter in the bread are close together and not spread out like in the air, when the matter in the air starts to come closer together it starts to make fog, because it is becoming more dense. Some more things that are heavy or dense are things like a big stereo speaker, an anvil, or even a big piece of wood used to build.
Explanation:
Students were having a catapult contest, launching a tennis ball with their home built devices. The winner launched a ball at 30 degrees from the ground at 6.0 m/s. How high does the ball go?
Answer:
The height reached by the ball=0.459 m
Explanation:
We are given that
[tex]\theta=30^{\circ}[/tex]
Initial speed, u=6 m/s
We have to find the maximum height reached by ball.
Maximum height reached by ball
[tex]h=\frac{u^2sin^2\theta}{2g}[/tex]
Where [tex]g=9.8m/s^2[/tex]
Substitute the values
[tex]h=\frac{6^2sin^230^{\circ}}{2\times 9.8}[/tex]
[tex]h=\frac{36\times \frac{1}{4}}{2\times 9.8}[/tex]
[tex]h=0.459 m[/tex]
Hence, the height reached by the ball=0.459 m
Why is it extremely dangerous to attempt to carry out a distillation in a completely closed apparatus
Answer:
The main reason is to avoid explosion
Explanation:
When we carry out distillation process, it will get to a point where gases/steam are released due to evaporation, if we do not create a channel for exit they will build up in the apparatus and will ultimately lead to explosion
A fast moving car is moving on a straight road with an acceleration of 2m/s2. How much time will it require to change the velocity from 20m/s to 40m/s.
Please quick
Answer:
10seconds
Explanation:
use the formula a=v final_v inital/time
In one of the classic nuclear physics experiments at the beginning of the 20th century, an alpha particle was accelerated toward a gold nucleus, and its path was substantially deflected by the Coulomb interaction. If the energy of the doubly charged alpha nucleus was 2.25 MeV, how close (in m) to the gold nucleus (79 protons) could it come before being deflected
Answer:
The answer is "[tex]1.01 \times 10^{-13}[/tex]"
Explanation:
Using the law of conservation for energy. Equating the kinetic energy to the potential energy.
[tex]KE=U=\frac{kqq'}{r}\\\\[/tex]
Calculating the closest distance:
[tex]\to r=\frac{kqq'}{KE}\\\\[/tex]
[tex]=\frac{k(2e)(79e)}{KE}\\\\=\frac{k(2)(79)e^2}{KE}\\\\=\frac{9.0\times 10^9 \ N \cdot \frac{m^2}{c}(2)(79)(1.6 \times10^{-19} \ C)^2}{(2.25\ meV) (\frac{1.6 \times 10^{-13} \ J}{1 \ MeV})}\\\\[/tex]
[tex]=\frac{9.0\times 10^9 \times 2\times 79\times 1.6 \times10^{-19}\times 1.6 \times10^{-19} }{(2.25 \times 1.6 \times 10^{-13}) }\\\\=\frac{3,640.32\times 10^{-29}}{3.6 \times 10^{-13} }\\\\=\frac{3,640.32}{3.6} \times 10^{-16}\\\\=1011.2 \times 10^{-16}\\\\=1.01 \times 10^{-13}[/tex]
Q011) The Doppler effect a. occurs when the frequency of sound waves received is lower if the wave source is moving toward you than if it's moving away. b. occurs when the pitch of a sound gets lower if the source is receding. c. is the basic explanation for the blue shift of light in our Universe. d. can be applied only to sound waves.
Answer:
Option (c) is correct.
Explanation:
The apparent change in the frequency of light due to the relative motion between the source and the observer is called Doppler's effect.
When the source is moving towards the observer which is at rest, the apparent frequency increases and if the observer is moving away the frequency of sound decreases.
It occurs for both light and sound.
So, to explain the blue shift of light in the universe is due to the Doppler's effect of light.
why does a desert cooler cool better than a hot dry day
On a hot dry day, the amount of water vapour present in atmosphere is less. Thus, water present inside the desert cooler evaporates more, thereby cooling the surroundings more. Hence, a desert cooler cools better on a hot dry day.
How did the English bill of rights impact the colonists views of government?  A. It established a process by which people could petition the government. B.It stated that freedom of religion should be respected by the government. C. It declared people’s freedom of political speech. D. It asserted that a rulers power are limited by a separate branch of government.
Answer:
C. It declared people’s freedom of political speech.
Explanation:
The English bill of rights limited the king's power and increased the power of the population. This is because after the declaration of rights, the king should take into account the will of the people so that he could be kept in power. On that occasion, the people should have understood that the king was not an absolute liber and that they had more political freedom to express when they felt the country was not being managed properly. This freedom was also given to the colonists, making them see themselves as an active factor within English politics and not a subordinate factor to the king.
Assertion: When I P+ Q I = I P- QI, then P must be perpendicular to Q. Reason: The relation will hold even when Q is a null vector.
Answer:
The assertion is true and reason is false.
Explanation:
Assertion: I P+ Q I = I P- QI, then P must be perpendicular to Q.
Reason : The relation will hold even when Q is a null vector.
Now
[tex]\left | P + Q \right |=\left | P - Q \right |\\\\P^2 + Q^2 + 2 P Q cos \theta =P^2 + Q^2 - 2 P Q cos \theta\\\\4 P Q cos \theta = 0 \\\\cos \theta = 0 \\\\\theta = 90 degree[/tex]
So, P and Q are perpendicular to each other.
So, the assertion is true.
Reason is false.
Define standard 1 killogram
" standard 1 meter
" standard 1 second
Answer:
-standard 1 kg : Kilogram (kg), basic unit of mass in the metric system.
-standard 1 meter: The standard metre is the length of the path travelled by light in vaccum during a time interval of 1/299792458 of a second.
- standard 1 second : The second (abbreviation, s or sec) is the Standard International ( SI ) unit of time.
Explanation:
HOPE IT HELPS YOU !!
The Sun's energy comes from which nuclear reaction?
Answer:
the sun energy comes from nuclea fution
An athlete runs around a circular track of radius 50 m and finishes at the same point where he began his journey. His total displacement in metre(s) is evaluated to be
Answer:
Explanation:
His displacement is 0 because he ended up exactly where he started.
A stream leaving a mountain range deposits a large part of its load in a __
Answer:
(n) alluvial fan sandbar
Explanation:
Is torque only produced when the force is applied perpendicular to the moment arm?
The Torque is only produced when the force is applied perpendicular to the moment arm.
What is moment of force?The equal and opposite force acting at a point from the axis of rotation is called the moment.
M = F x r
Moment of force is also called as Torque.
Moment arm is the distance of the point of application of force from the axis of rotation of the body.
Thus, the perpendicular component only, produces the torque.
Learn more about moment of force.
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A lamp is connected to a 230 V mains supply. A current of 4 A flows through the lamp for 30 seconds.
Answer:
The energy dissipated is 27600 J.
Explanation:
Voltage, V = 230 V
Current, I = 4 A
time, t = 30 s
The energy is given by
E = V I t
E = 230 x 4 x 30
E = 27600 J
Does the colour of an object affect the rate of evaporation?
Which items did Mendeleev write down on note cards while he was observing
different elements?
A. Buoyancy
B. Density
C. Color
D. Atomic mass
Mendeleev wrote down atomic mass
Answer:
A. Buoyancy.
hope it helps
stay safe healthy and happy..Which statement best describes how pigments affect what colors humans
see?
A. Pigments separate white light into different colors based on
wavelengths. Humans see colors within a certain range of
wavelengths.
B. Pigments emit light in different colors. Humans see the color that
a certain pigment emits.
C. Pigments reflect some wavelengths of visible light and absorb
others. Humans see the absorbed wavelengths.
D. Pigments reflect some wavelengths of visible light and absorb
others. Humans see the reflected wavelengths.
Answer:
C
Explanation:
Pigments reflect some wavelength of visible light and absorb
show that pv=nrt has the same unit with energy
Answer:
It is proved.
Explanation:
PV = n R T
where, P is the pressure, V is the volume, n is the number of moles, R is the gas constant, T is the absolute temperature.
Unit of pressure is Pascal= Newton/square meter = [tex][ML^{-1}T^{-2}][/tex]
Unit of volume is cubic meter = [tex][L^{3}][/tex]
So, the unit of P V
[tex][ML^{-1}T^{-2}] \times [L^{3}]\\\\[ML^2T^{-2}}[/tex]
[tex][ML^{2}T^{-2}][/tex]
It is same as the unit of energy.
hence proved.
The designer tested how the number of cells affected the number of steps that could
be taken before the lights stopped working.
Figure 2 shows the results.
Figure 2
1600
1400
1200
1000
Number of
steps in
800
thousands
600
400
200
0
1
5
2 3 4
Number of cells
1
3
Determine how many more steps could be taken when the number of cells was
increased from 3 to 5
[2 marks
Number of steps
=
thousand
Answer:
1000.
Explanation:
Thousand more steps could be taken when the number of cells was increased from 3 to 5 because in the data, the number of cells i.e. 5 was achieved on 1000 steps. According to the data, the number of cells i.e. 1 was achieved on 800 steps, the number of cells i.e. 5 was achieved on 1000 steps, the number of cells i.e. 2 was achieved on 600 steps, the number of cells i.e. 3 was achieved on 400 steps and the number of cells i.e. 4 was achieved on 200 steps. So we can say that 1000 steps are needed for the number of cells increased from 3 to 5.