Answer:
v = 9.812 m/s
Explanation:
Given that,
The initia speed of a car, u = 6.5 m/s
Acceleration of the car, a = 0.92 m/s²
Time, t = 3.6 s
We need to find the final velocity of the car. Let the final velocity be v. Using equation of motion to find it as follows :
v = u +at
Putting all the values,
v = 6.5+(0.92)(3.6)
v = 9.812 m/s
So, the final velocity of the car is 9.812 m/s.
The water drops fall at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at the instant the first touches the ground. How far above the ground is the second drop at that instant?
I will mark brainliest
Answer:
The second drop is 3.75 m above the ground
Explanation:
Free Fall Motion
A free-falling object falls under the sole influence of gravity without air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is [tex]g = 9.8 m/s^2[/tex].
The distance traveled by a dropped object is:
[tex]\displaystyle y=\frac{gt^2}{2}[/tex]
If we know the height h from which the object was dropped, we can find the time it takes fo hit the ground:
[tex]\displaystyle t=\sqrt{\frac{2y}{g}}[/tex]
When the first drop touches the ground there are two more drops in the air: the second drop still traveling, and the third drop just released from the tap.
The total time taken for the first drop to reach the ground is:
[tex]\displaystyle t_1=\sqrt{\frac{2*5}{g}}[/tex]
[tex]t_1 = 1.01\ s[/tex]
Half of this time has taken the second drop to fall:
[tex]t_2 = 1.01\ s/2=0.505\ s[/tex]
It has fallen a distance of:
[tex]\displaystyle y_2=\frac{9.8(0.505)^2}{2}[/tex]
[tex]y_2 = 1.25\ m[/tex]
Thus its height is:
h = 5 - 1.25 = 3.75
The second drop is 3.75 m above the ground
The terms transverse or longitudinal are often used to describe the types of pulses. To what feature of a pulse do these terms refer:____________
Explanation:
Transverse pulse or waves are those in which elements of the pulse move perpendicular to the propagation of the pulse. Whereas, Longitudinal waves are those in which elements of the wave are in same direction as the propagation of the wave. For example Light is a transverse pulse whereas sound is a longitudinal wave.
Energy Transformation
A car with a mass of 2000 kg is traveling down the highway at a constant 20 m/s. How much kinetic energy does it have?
100 J
50 J
400.000 J
40.000 J
Answer:
K =400000 J
Explanation:
Kinetic Energy
Is the energy an object has due to its state of motion. It's proportional to the square of the speed.
The equation for the kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]
Where:
m = mass of the object
v = speed at which the object moves
The kinetic energy is expressed in Joules (J)
The car has a mass of m=2000 Kg and travels at v=20 m/s. Calculating the kinetic energy:
[tex]\displaystyle K=\frac{1}{2}2000*20^2[/tex]
Calculating:
K =400000 J
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]
Exercising helps reduce?
Answer:
stress,depression and anxiety by improving self esteem.
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.
motion is a change in
What is the final velocity of an object that starts from rest and accelerates uniformly at 4
m/s2 over a distance of 8 m?
Answer:
8m/s
Explanation:
Given parameters:
Initial velocity = 0m/s
Acceleration = 4m/s²
Distance = 8m
Unknown:
Final velocity = ?
Solution:
To solve this problem, we use the right motion equation and find the unknown.
The right motion equation to solve this problem is given as :
v² = u² + 2aS
v is the final velocity
u is the initial velocity
a is the unknown acceleration
S is the distance
Now insert the parameters and solve;
v² = 0² + 2 (4) (8)
v² = 64
v = 8m/s
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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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
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
Please help meeeee
For a velocity versus time graph how do you know what the velocity is at a certain time? How do you know the acceleration at a certain time?
Answer:
Explained below
Explanation:
For a velocity time graph, the y - axis will represent velocity while the x - axis will represent time.
Now, to calculate velocity at a certain time t, we will draw a perpendicular line from the time on the x-axis to the graph line and trace the horizontal line from that point to the y-axis which will give the corresponding velocity at that time.
Now, for the acceleration at a time t. After getting the velocity like explained above, we now divide the velocity by the time.
Which has more momentum, a 2000 lb car moving at 100 km/hr or a 4000 lb truck moving at 50 km/hr ?
Answer:
The truck and car have the same momentum.
Explanation:
[tex]m_1[/tex] = Mass of car = [tex]2000\ \text{lb}=2000\times0.45359237\ \text{kg}[/tex]
[tex]v_1[/tex] = Velocity of car = [tex]\dfrac{100}{3.6}\ \text{m/s}[/tex]
[tex]m_2[/tex] = Mass of truck = [tex]4000\times0.45359237\ \text{kg}[/tex]
[tex]v_2[/tex] = Velocity of truck = [tex]\dfrac{50}{3.6}\ \text{m/s}[/tex]
Momentum of car
[tex]p_1=m_1v_1\\\Rightarrow p_1=2000\times0.45359237\times \dfrac{100}{3.6}\\\Rightarrow p_1=25199.58\ \text{kg m/s}[/tex]
Momentum of the truck
[tex]p_2=m_2v_2\\\Rightarrow p_2=4000\times0.45359237\times \dfrac{50}{3.6}\\\Rightarrow p_2=25199.58\ \text{kg m/s}[/tex]
Both the truck and car have the same momentum of [tex]25199.58\ \text{kg m/s}[/tex].
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:
A contact lens is made of plastic with an index of refraction of 1.60. The lens has an outer radius of curvature of 2.08 cm and an inner radius of curvature of 2.48 cm. What is the focal length of the lens?
Answer:
The value [tex]f = 21.49 \ cm[/tex]
Explanation:
From the question we are told that
The index of refraction is [tex]n = 1.60[/tex]
The outer radius of curvature is [tex]R = 2.08 \ cm = 0.0208 \ m[/tex]
The inner radius is [tex]r = 2.48 \ cm = 0.0248 \ m[/tex]
Generally from Maker's equation we have that
[tex]\frac{1}{f} = [n - 1 ][\frac{1}{(R)} - \frac{1}{r} ][/tex]
=> [tex]\frac{1}{f} = [1.60 - 1 ][\frac{1}{( 0.0208 )} - \frac{1}{0.0248} ][/tex]
=> [tex]\frac{1}{f} = 4.65[/tex]
=> [tex]f = 0.2149 \ m[/tex]
=> [tex]f = 21.49 \ cm[/tex]
Two forces of 50 N and 30N respectively, are acting on an object. Find the net force (in N) on the object if
A) the forces are acting in the same direction.. B) Together, forces are acting in opposite directions
Answer:
A) 80 N
B) 20 N
Explanation:
A) If the forces acting are in the same direction, then the net force will be a sum of both so many faces..
Thus;
ΣF = 50 + 30
ΣF = 80 N
B) If the forces are acting in the in opposite directions with the larger force pointing in the positive y-axis then, the net force is;
ΣF = 50 - 30
ΣF = 20 N
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.
A diver 50 m deep in 10∘C fresh water exhales a 1.0-cm-diameter bubble. What is the bubble's diameter just as it reaches the surface of the lake, where the water temperature is 20∘C?
Answer:
18.2mm
Explanation:
D = 50m
T1 = 10+273 = 283K
T2 = 20+273 = 293K
R1 = 5x10^-3
Absolute pressure at 50m
P1 = pA + pwateer x g x d
= 101000+ 1000x9.81x50
= 591500pa
New volume of bubble
= P1v1/T1 = p2v2/T2
= 125x10^-9 x 591500x293/101000*283
= 757.9x10^-9m³
R2 = 9.2x10^-3
D2 = 18.2mm
Or 1.82cm
Question 12 of 20
To produce a magnetic field, what does an electromagnet require?
A. A solenoid with no current flowing through it
B. A current flowing through a coil of wire
C. A core made from a magnetic material
D. A copper core
Answer:
B a current flowing through a coil of wire :)
Explanation:
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]
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 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.
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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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 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]
A 125 g pendulum bob hung on a string of length 35 cm has the same period as when the bob is hung from a spring and caused to oscillate. What is the spring’s elastic constant?a) 3.5 N/mb) 5.2 N/mc) 1.9 N/md) 27 N/m
Answer:
k = 3.5 N/m
Explanation:
It is given that the time period the bob in pendulum is the same as its time period in spring mass system:
[tex]Time\ Period\ of\ Pendulum = Time\ Period\ of\ Spring-Mass\ System\\2\pi \sqrt{\frac{l}{g}} = 2\pi \sqrt{\frac{m}{k}[/tex]
[tex]\frac{l}{g} = \frac{m}{k}\\\\ k = g\frac{m}{l}[/tex]
where,
k = spring constant = ?
g = acceleration due to gravity = 9.81 m/s²
m = mass of bob = 125 g = 0.125 kg
l = length of pendulum = 35 cm = 0.35 m
Therefore,
[tex]k = (9.81\ m/s^2)(\frac{0.125\ kg}{0.35\ m})\\\\[/tex]
k = 3.5 N/m
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:
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
2
Look at the circult dlagram.
Direction
of current
Battery
Bulb-
What type of circuit is shown?
A. open series circult
B. closed series circuit
C. open parallel circult
D. closed parallel circult
The direction of the current from the positive to the negative battery terminals and the fact that the bulbs are connected in parallel to each other suggests that this circuit is a Closed Parallel Circuit. The correct option is D.
What is the difference between open and closed circuits?An open circuit and a closed circuit are two types of electrical circuits that describe the flow of electrical current through a circuit.
An open circuit is a circuit in which there is a break in the path of the current, meaning that the current cannot flow through the circuit. In an open circuit, the switch is in the "off" position or there is a broken wire, and so no electrical current can flow through the circuit. This means that there is no voltage or electrical energy being transferred from the source to the load.
On the other hand, a closed circuit is a circuit in which there is a complete path for the current to flow through, meaning that the current can flow through the circuit. In a closed circuit, the switch is in the "on" position, and there is a continuous path for the current to flow from the source to the load and back to the source. This means that there is voltage and electrical energy being transferred from the source to the load.
Here in this question,
The direction of the current from the positive to the negative battery and the fact that the bulbs are connected in parallel to each other suggests that this circuit is a Closed Parallel Circuit.
In a closed parallel circuit, the components are connected in parallel to each other, meaning that they are connected to the same two points in the circuit and the current has multiple paths to flow through. The voltage across each component is the same, and the total current flowing through the circuit is divided among the components according to their resistance.
In contrast, an open series circuit is a circuit in which the components are connected in series, meaning that they are connected end to end in a single path, with no other branch points for the current to follow. If one component fails, the circuit becomes open and the current stops flowing.
Therefore, based on the information provided, the circuit described in the question is a Closed Parallel Circuit.
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a 1220 kg automobile travels at 75 m/s. what net work would be required to bring it to a stop
Answer:
W = - 3431250 [N]
Explanation:
In order to solve this problem, we must use the theorem of work and energy conservation. This theorem tells us that the initial mechanical energy of a body plus the work done on this body must be equal to the final mechanical energy of the body. We must remember that the mechanical energy of a body is equal to the sum of kinetic energies plus potential energy plus elastic energy.
In this problem, we only have kinetic energy.
[tex]E_{1}+W_{1-2}=E_{2}\\where:\\E_{1}=E_{pot}+E_{kine}+E_{elas}\\E_{pot} = 0\\E_{elas}=0\\E_{kine}=\frac{1}{2} *m*v^{2}[/tex]
And we have:
m = mass = 1220 [kg]
v = velocity = 75 [m/s]
As the carriage stops the final kinetic energy is zero.
Now replacing:
[tex]\frac{1}{2} *1220*(75)^{2} +W_{1-2}=0\\W_{1-2}= - 3431250[N][/tex]
Note: The negative force means that the force has to be carried out by the carriage. That is, no external force acts on the car to stop it.