Answer:
speed before landing = 3.9 m/s (3 s.f.)
Explanation:
As rock is released from rest, u = 0 m/s a = 1.62 m/s² t = 2.4 s v = ?
v = u + at
v = 0 + (1.62 x 2.4)
v = 3.888 = 3.9 s (3 s.f.)
Hope this helps!
The speed of the rock before hitting the ground is 3.89 m/s
The given parameters;
acceleration due to gravity on moon, g = 1.62 m/s²
time taken for the object to fall, t = 2.4 s
To find:
the speed of the object before hitting the ground;The maximum height of fall of the rock is calculated as;
[tex]h = v_0t + \frac{1}{2} gt^2\\\\v_0 = 0\\\\h = \frac{1}{2} gt^2\\\\h = 0.5 \times 1.62 \times 2.4^2 \\\\h = 4.67 \ m[/tex]
The speed of the rock before hitting the ground is calculated as;
[tex]v_f^2 = v_0 ^2 + 2gh\\\\v_f^2 = 0 + 2\times 1.62 \times 4.67\\\\v_f^2 = 15.13\\\\v_f = \sqrt{15.13} \\\\v_f = 3.89 \ m/s[/tex]
Thus, the speed of the rock before hitting the ground is 3.89 m/s
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A wire is carrying current vertically downward. What is the direction of the force due to Earth's magnetic field on the wire?
A wire is carrying current vertically downward.
What is the direction of the force due to Earth's magnetic field on the wire?
a) horizontally towards the east
b) horizontally towards the west
c) horizontally towards the south
d) horizontally towards the north vertically upward
Answer: The correct option is A ( horizontally towards the east)
Explanation:
Magnetic field is a region around a magnet or a current- carrying conductor, where a magnetic force is experienced. The magnetic effect of electric current was first discovered in the early 1820 by Oersted. Using a wire that had current flowing through it and a pivoted magnetic needle, he discovered that the direction of deflection depended on the direction of the current and whether the wire was above or below the needle.
From the way the needle turns when current when current carrying wire is held parallel to it, he therefore concluded that:
--> a current has magnetic field all round it,
--> the magnetic field is in a direction perpendicular to the current.
The above discovery was now modified in Fleming's left hand rule which states that when conductor carrying current is placed in a magnetic field, the conductor will experience a force perpendicular to both the field and the flow of current.
Therefore from the question, a vertical wire carrying current in DOWNWARD direction is placed in a HORIZONTAL magnetic field directed to the NORTH. The direction of the force on the wire is to the EAST.
Conveyor belts are often used to move packages around warehouses. The conveyor shown below moves packages at a steady 4.0 m/s. A 500 N employee decides to catch a ride by sitting on a 1,000 N box for a 50 m trip as shown below:
What is the work done by the employee on the box?
Answer:
0 j
Explanation:
The work done by the employee on the box at the given zero displacement is 0 J.
The given parameters;
Constant velocity of the conveyor, v = 4 m/sWeight of the employee, W = 500 NWeight of the box, W = 1,000 NDistance of the trip, h = 50 mThe work done by the employee on the box is calculated as follows;
W = Fd
where;
F is the applied force on the box by employee = weight of the employeed is the distance through which the box is movedSince the employee sits on the box without moving it, the distance moved by the box = 0
W = 500 x 0
W = 0 J
Thus, the work done by the employee on the box is 0 J.
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Why does a stop sign appear red?
Answer:
because it’s suppose to be red like a stop light.
Explanation:
So it tells you to stop
A particular engine has a power output of 5 kW and an efficiency of 30%. If the engine expels 6464 J of thermal energy in each cycle, find the heat absorbed in each cycle. Answer in units of J.
Answer:
The heat absorbed in each cycle is 9,234.286 J
Explanation:
Given;
power output, P = 5 kW = 5,000 W
efficiency of the engine, e = 30 % = 0.3
thermal heat expelled, [tex]Q_c[/tex] = 6464 J
let the heat absorbed = [tex]Q_h[/tex]
The efficiency of the engine is given as;
[tex]e = \frac{W}{Q_h} = \frac{Q_h-Q_c}{Q_h} = \frac{Q_h}{Q_h} - \frac{Q_c}{Q_h} = 1-\frac{Q_c}{Q_h}\\\\e = 1-\frac{Q_c}{Q_h}\\\\0.3 = 1-\frac{Q_c}{Q_h}\\\\\frac{Q_c}{Q_h} = 1-0.3\\\\\frac{Q_c}{Q_h} = 0.7\\\\Q_h = \frac{Q_c}{0.7} \\\\Q_h = \frac{6464}{0.7} = 9,234.286 \ J.[/tex]
Therefore, the heat absorbed in each cycle is 9,234.286 J.
HELP right awayyy !!!
Answer:
Question 4 is actually Acceleration
A swimmer speeds up from 1.1 m/s to 3.2 m/s during the last 13.0 seconds of the race. What is the acceleration of the swimmer?
Answer:
a = 0.16 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o}+a*t\\[/tex]
where:
Vf = final velocity = 3.2 [m/s]
Vo = initial velocity = 1.1 [m/s]
t = time = 13 [s]
a = acceleration [m/s²]
Now replacing:
[tex]3.2=1.1+a*13\\2.1=13*a\\a=0.16[m/s^{2} ][/tex]
if a certain car, going with speed v1, rounds a level curve with a radius r1, it is just on the verge of skidding. if its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:
Answer:
The correct answer is 4R1
Explanation:
According to the given scenario ,the radius of the tightest curve on the same road without skidding is as follows:
As we know that
Centeripetal Acceleration is
= v^2 ÷ r
In the case when velocity becomes 2 times so the r would be 4 times
So, the radius of the tightest curve on the same road without skidding is 4R1
What causes the magnetic field around the wire?
Magnetic field
O A. An electric current
O B. An electric field
PREVIOUS
An electric current causes the magnetic field around the wire. The correct answer is A.
The magnetic field around a wire is caused by the flow of electric current through the wire. When an electric current passes through a wire, it generates a magnetic field that forms circular lines of magnetic flux around the wire. This phenomenon is described by Ampere's law, which states that a magnetic field is produced by an electric current and its strength is directly proportional to the magnitude of the current.
The relationship between the electric current and the magnetic field can be understood using the right-hand rule. If you wrap your right hand around the wire with your thumb pointing in the direction of the current, the curled fingers indicate the direction of the magnetic field lines.
Therefore, an electric field is generated by an electric charge, not by an electric current. While an electric field can exist around a wire if there is a potential difference (voltage) applied across it, it is the flow of electric current that primarily generates the magnetic field.
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The scientific method can easily be misinterpreted as ___________. Question 1 options: a great magical trick, or slide of hands, rather than factual an "auto mechanics" guide to Science Investigation a "cookbook" recipe for performing scientific investigations the perfect method for finding the answers to all questions
Answer:
I think the answer is
a "cookbook" recipe for performing scientific investigations
Explanation:
define electric potential at a point and find expression for it.
Answer:
Recall that the electric potential is defined as the potential energy per unit charge, i.e. V=PEq V = PE q . ... The equation for the electric potential due to a point charge is V=kQr V = kQ r , where k is a constant equal to 9.0×109 N⋅m2/C2.
Explanation:
you pick up a 3.8 kg can of paint from the ground a lift it to a height of 1.4 m. you hold the can stationary for half a minute, waiting for a friend on a ladder to take it. how much work do you do duting this time (when the can of paint is stationary)?
Answer:
No work
Explanation:
During the time of holding the can stationary, no work is being done by the person carrying the can.
The can is simply at rest.
Work is done when a force is applied to move a body through a certain distance.Work done = force x distance
In the instance given in this problem, only when the paint was lifted up is work done.
When the paint is stationary and being supported by the person, no work is done.
if an atom has two protons and three electrons than the atom is
Answer:
negative 1 charge
Explanation:
one electron is extra so there will be -1 chargw
If an atom has two protons and three electrons than the atom is negatively charged.
What is an atom?An atom is a matter particle that defines a chemical element uniquely. An atom is made up of a central nucleus and one or more negatively charged electrons.
The nucleus is positively charged and contains one or more protons and neutrons, which are relatively heavy particles.
It is made up of protons, which have a positive charge, and neutrons, which do not have any charge. Protons, neutrons, and the electrons that surround them are long-lived particles found in all natural atoms.
The modern atomic hypothesis was founded by John Dalton, a great chemist. His atom, on the other hand, was like a solid billiard ball.
An atom is negatively charged if it has two protons and three electrons.
Thus, the given atom bears negative charge.
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An object 2.7 cmtall is placed12 cmin front of a mirror. •What type of mirror and what radius of curvature are needed to createan upright image that is 5.4 cm in height? •What is the magnification of the image?
Answer:
a. Concave mirror, radius of curvature = 16 cm b. magnification = 2
Explanation:
a. Since the image is upright and larger than the object, we need a concave mirror.
We know image height, h'/object height, h = -image distance, d'/object distance, d
h'/h = -d'/d
Using the real is positive convention,
h'= + 5.4 cm, h = + 2.7 cm and d = + 12 cm.
So, + 5.4 cm/+ 2.7 cm = -d'/+ 12 cm
2 = -d'/12
d' = -2 × 12 cm
= -24 cm
Using the mirror formula 1/d + 1/d' = 2/r where r = radius of curvature of the mirror
1/+12 + 1/- 24 = 2/r
1/12(1 - 1/2) = 2/r
1/12(1/2) = 2/r
1/24 = 2/r
r/2 = 24
r = 2 × 24
r = 48 cm
b.
magnification = image height, h'/object height,h = + 5.4 cm/+ 2.7 cm = 2
What is the period of an object that makes 6 revolutions a minute?
Answer:
T = 10 s
Explanation:
First, we need to find the frequency of the object as follows:
[tex]Frequency = f = \frac{Speed\ in\ rpm}{60}[/tex]
where,
Speed = Angular Speed = 6 rpm
Therefore,
[tex]f = \frac{6\ rpm}{60}\\\\f = 0.1\ Hz[/tex]
Now, for time period (T):
[tex]Time\ Period = T = \frac{1}{f}\\\\T = \frac{1}{0.1\ Hz}\\\\[/tex]
T = 10 s
A 3 kg mass is travelling in a circle of 0.1 m radius with a speed of 2 m/s. What is the centripetal acceleration?
a = v² / R = (2 m/s)² / (0.1 m) = 40 m/s²
Is electricity matter?
EXPLAIN.
Answer:
Yes it is matter
Explanation:
In physics, usually the word "electricity" isn't really used. "Electric current" is more common, and is defined as the flow of charges, where the charges are held by particles (electrons). Electrons have mass, so they are definitely matter.
Energy stored because of an object's height above the Earth's surface is_____energy.
nuclear
gravitational
electrical or chemical
Which wave has high enough energy to cause damage to skin and sometimes cancer?
Answer: All UV can have harmful effects on biological matter (such as causing cancers) with the highest energies causing the most damage.
Explanation:
Thomas the Tank Engine (a train) is going 80 m/s and slows down to 30 m/s over a period of 30s. What is his deceleration? Acceleration= (final velocity-initial velocity)/ time A. -1.67 m/s/s B. 0.67 m/s/s C. -50 m/s/s D. 50 m/s/s
Answer: D
Explanation:
what is the main cause of seafloor spreading?
Answer:
As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense.
Explanation:
Answer: The main cause of sea floor spreading are the directions and force of the moving tectonic plates.
Explanation:
How does light move?
Answer:
Light travels as a wave. But unlike sound waves or water waves, it does not need any matter or material to carry its energy along. This means that light can travel through a vacuum—a completely airless space. It speeds through the vacuum of space at 186,400 miles (300,000 km) per second.
Explanation:
Hope this helps :))
A diffraction pattern is formed on a screen 150 cm away from a 0.500-mm-wide slit. Monochromatic 546.1-nm light is used. Calculate the fractional intensity I/Imax at a point on the screen 4.10 mm from the center of the principal maximum.
Solution :
The expression for the intensity of light is given by :
[tex]$I=I_{max}\left(\frac{\sin \frac{\pi a \sin \theta}{\lambda}}{\frac{\pi a \sin \theta}{\lambda} }\right)^2$[/tex]
For a small angle, θ
sin θ = tan θ
[tex]$=\frac{y}{L}$[/tex]
Therefore the above equation becomes,
[tex]$I=I_{max}\left(\frac{\sin \frac{\pi a y}{\lambda L}}{\frac{\pi a y}{\lambda L} }\right)^2 $[/tex]
The given data is
λ = 546.1 nm
L = distance between the slit and the screen = 140 cm
= 1.40 m
a = width of the slit
= [tex]$0.50 \times 10^{-3} \ m$[/tex]
Therefore,
[tex]$I=I_{max}\left(\frac{\sin \frac{\pi \times 0.50 \times 10^{-3} \times 4.10 \times 10^{-3}}{546.1 \times 10^{-9} \times 1.20}}{\frac{\pi \times 0.50 \times 10^{-3} \times 4.10 \times 10^{-3}}{546.1 \times 10^{-9} \times 1.20} }\right)^2 $[/tex]
[tex]$=\left(\frac{0.170}{9.82}\right)^2$[/tex]
[tex]$= 2.89 \times 10^{-4} \ I_{max}$[/tex]
Therefore the fractional intensity is [tex]$\frac{I}{I_{max}}= 2.89 \times 10^{-4} $[/tex]
are aliens real in 2020
Answer:
i believe that they are or there's something out there
Explanation:
:)
Plz help
Fill in the blank with the correct observation from the simulation.
As the days go on, the distance that the moon is from the sun in the night sky
A. Stays the same
B. Decreases
C. Increases
Starting at New Moon, The visual distance increases for about 2 weeks, then decreases for about the next 2weeks, until the next New Moon.
On the average, it changes by about 12° per day.
. Emily pushes a 38.8 kg grocery cart of groceries by exerting a 76.0 N force on the handle inclined at 40.0 degrees below the horizontal. What are:
a. The horizontal and vertical components of Emily’s force
b. The acceleration of the cart?
Answer:
a) [tex]F_{x} = 58.2 N[/tex]
[tex] F_{y} = 48.9 N [/tex]
b) a = 1.5 m/s²
Explanation:
a) The horizontal and vertical components of Emily's force can be found knowing the angle and the exerted force.
Since the handle is inclined at 40.0° below the horizontal we have:
[tex] F_{x} = |F|*cos(\theta) = 76.0 N*cos(40) = 58.2 N [/tex]
[tex] F_{y} = |F|*sin(\theta) = 76.0 N*sin(40) = 48.9 N [/tex]
b) The acceleration of the car can be calculated as follows:
[tex] F_{x} = ma [/tex]
We used the horizontal component of the force because the cart is moving in that direction.
[tex] a = \frac{F_{x}}{m} = \frac{58.2 N}{38.8 kg} = 1.5 m/s^{2} [/tex]
Hence, the acceleration of the car is 1.5 m/s².
I hope it helps you!
If 65 kW is to be transmitted over two 0.100 ohm lines, estimate how much power is saved if the voltage is stepped up from 120 V to 1200 V
Answer: 5.91kw
Explanation:
given data:
power = 65kw
voltage stepped up = 120v t0 1200
R 0.100
Solution:
when the it is stepped to 120v
[tex]P = VI \\65000/ 120I\\ I = 541.7A\\[/tex]
power loss
[tex](I^{2} )R*2\\= (541.7^{2})0.100*2\\= 58536.2w[/tex]
when it is stepped to 1200v
[tex]\frac{65000}{1200} \\ I = 54.17A\[/tex]
[tex](I^{2} )R*2\\= (54.17^{2})0.100*2\\= 586.9w[/tex]
total power saved
[tex]= 65kw - 58.5kw - 0.59kw\\= 5.91kw[/tex]
A student adds two vectors of magnitudes 48 m and 22 m. What are the maximum and minimum possible values for the resultant of these two vectors.
Answer:
Maximum=70 m
Minimum=26 m
Explanation:
Vector Addition
Since vectors have magnitude and direction, adding them takes into consideration not only the magnitudes but also their respective directions. Two vectors can be totally collaborative, i.e., point to the same direction, or be totally opposite. In the first case, the magnitude of the sum is at maximum. Otherwise, it's at a minimum.
Thus, the maximum magnitude of the sum is 48+22 = 70 m and the minimum magnitude of the sum is 48-22= 26 m
Two wave pulses pass each other on a string. The pulse traveling toward the right has positive amplitude, whereas the pulse traveling toward the left has equal amplitude in the negative direction. What happens when they occupy the same region of space at the same time?
a. constructive interference occurs
b. destructive interference occurs.
c. a standing wave is produced.
d. a traveling wave is produced.
e. a wave pulse is produced.
Answer:
destructive interference occurs
A person holds a ladder horizontally at its center. Treating the ladder as a uniform rod of length 4.15 m and mass 7.98 kg, find the torque the person must exert on the ladder to give it an angular acceleration of 0.396 rad/s2.
Answer:
4.535 N.m
Explanation:
To solve this question, we're going to use the formula for moment of inertia
I = mL²/12
Where
I = moment of inertia
m = mass of the ladder, 7.98 kg
L = length of the ladder, 4.15 m
On solving we have
I = 7.98 * (4.15)² / 12
I = (7.98 * 17.2225) / 12
I = 137.44 / 12
I = 11.45 kg·m²
That is the moment of inertia about the center.
Using this moment of inertia, we multiply it by the angular acceleration to get the needed torque. So that
τ = 11.453 kg·m² * 0.395 rad/s²
τ = 4.535 N·m
The Torque will be "4.535 N.m".
Given:
Mass of ladder,
m = 7.98 kgLength of ladder,
L = 4.15 m
The moment of inertia will be:
→ [tex]I = \frac{mL^2}{12}[/tex]
[tex]= \frac{7.98\times (4.15)^2}{12}[/tex]
[tex]= \frac{7.98\times 17.2225}{12}[/tex]
[tex]= 11.45 \ kg.m^2[/tex]
hence,
The torque will be:
→ [tex]\tau = 11.453\times 0.395[/tex]
[tex]= 4.535 \ N/m[/tex]
Thus the above approach is correct.
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Mary and John are seated on a bench a distance 2 part. Suddenly, John moves closer to Mary and claims that he has been drawn by the gravitational force. Is John’s claim justifiable? Show quantitatively. (Assume the masses of John and Mary are 67 and 55 respectively, and the coefficient of static friction between John and the bench is 0.15). [4]
Answer:
no
gravitational force between them is far smaller than the frictional force between the guy and the bench