Answer:
96.7 s
Explanation:
Time of flight in projectile can be calculated thus:
T = 2 × u × sin ϴ/ g
Where;
T = time of flight (s)
u = initial velocity (m/s)
ϴ = Angle of projectile (°)
g = acceleration due to gravity (9.8m/s²)
Based on the provided information; u = 670m/s, ϴ = 45°
Hence, using T = 2.u.sin ϴ/ g
T = 2 × 670 × sin 45° ÷ 9.8
T = 1340 × 0.7071 ÷ 9.8
T = 947.52 ÷ 9.8
T = 96.68
T = 96.7s
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
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]
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.
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
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]
motion is a change in
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].
weight of Ali is 500andN.he is standing on the ground with an area of 0.025 m^2 area .we can find pressure under his feet. what is it?
Answer:
20000 Pa
Explanation:
Pressure is defined as the force per unit area.
Mathematically : P =F/A where F is force and A is area
Force = 500 N
Area= 0.025 m²
P= 500/0.025
P= 20000 Pa
What is the frequency of a pendulum that is moving at 30
m/s with a wavelength of 0.32 m?
Answer:
85.7Hz
Explanation:
v=f*λ
f = frequency
λ = wavelength
The frequency of the pendulum which is moving with a velocity of 30 m/s with a wavelength of 0.32 m is 93.75 Hz.
What is Frequency?The term frequency refers to the number of waves which are passing a fixed point in the unit time. Frequency also describes the number of cycles or the vibrations which are undergone during one unit of time through an object or a body in periodic motion. The SI unit of frequency is Hertz (Hz).
Wavelength = Velocity/ Frequency
Frequency = Velocity/ Wavelength
Frequency = 30/ 0.32
Frequency = 93.75 Hz
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Forces that cancel each other are called_ forces \
Answer:
balanced forces
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 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]
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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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:
The batter swings and misses the 40 m/s (90 mph) fastball, and the ball (mass 150 grams) ends up at rest in the catcher's mitt. How much work does the catcher perform on the ball
Answer:
The work done by the catcher is 120 J.
Explanation:
Given;
velocity of the fastball, v = 40 m/s
mass of the fastball, m = 150 g = 0.15 kg
Based on work-energy theorem, the work done by the catcher is equal to the kinetic energy of the fastball.
The kinetic energy of the fastball is given as;
K.E = ¹/₂mv²
K.E = ¹/₂ x 0.15 x 40²
K.E = 120 J
Therefore, the work done by the catcher is 120 J.
A 10-mm-diameter cable is strung between a series of poles that are 50 m apart. Determine the horizontal force this cable puts on each pole if the wind velocity is 34 m/s.
Answer:
The value is [tex]F = 562.7 \ N[/tex]
Explanation:
From the question we are told that
The diameter is [tex]d = 10 \ mm = 0.01 \ m[/tex]
The distance between the poles is L = 50 m
The velocity of the wind is [tex]v = 34 \ m/s[/tex]
Generally the horizontal force the cable puts on each other is mathematically represented as
[tex]F = \frac{1}{2} * C_D * \rho * v^2 * A[/tex]
Here A is the area of the rope(i.e assuming the rope to be a cylinder ) which is mathematically represented as
[tex]A = L * d[/tex]
=> [tex]A = 0.01 * 50[/tex]
=> [tex]A = 0.5[/tex]
Here [tex]C_D[/tex] is the coefficient of discharge of the rope and the value is [tex]C_D = 1.5[/tex]
[tex]\rho[/tex] is the density of air with value [tex]\rho = 1.225 \ kg/m^3[/tex]
So
[tex]F = \frac{1}{2} * C_D * \rho * v^2 * A[/tex]
=> [tex]F = \frac{1}{2} * 1.5 * 1.225 * 34^2 * 0.5[/tex]
=> [tex]F = 562.7 \ N[/tex]
Exercising helps reduce?
Answer:
stress,depression and anxiety by improving self esteem.
Comparing infrared and ultraviolet, we can say that __________. Comparing infrared and ultraviolet, we can say that __________.
Answer:
The appropriate response will be "Infrared has a longer wavelength and lower photon energy".
Explanation:
This same Infrared emission falls between some of the observable but rather microwave components of the electric spectrum. Infrared rays have quite a wavelength longer than ultraviolet light. And indeed the frequency of radiation remains smaller, unlike UV rays. Even before we recognize that the energy (photon) of the visible region has always been equal to the total of waves. Infrared thus has smaller photon intensity versus ultraviolet.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
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
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.
Two friends grab different sides of a textbook and pull with forces of 6.7 N to the east and 4.4 N to the west, respectively. What would be the magnitude and direction of the force a third friend would need to exert on the textbook in order to balance the other two forces?
Explanation:
This equation for acceleration can be used to calculate the acceleration of an object that is acted on by a net force. For example, Xander and his scooter have a total mass of 50 kilograms. Assume that the net force acting on Xander and the scooter is 25 Newtons. What is his acceleration? Substitute the relevant values into the equation for acceleration:
Answer:
a=Fm=25 N50 kg=0.5 Nkg
The Newton is the SI unit for force. It is defined as the force needed to cause a 1-kilogram mass to accelerate at 1 m/s2. Therefore, force can also be expressed in the unit kg • m/s2. This way of expressing force can be substituted for Newtons in Xander’s acceleration so the answer is expressed in the SI unit for acceleration, which is m/s2:
a=0.5 Nkg=0.5 kg⋅m/s2kg=0.5 m/s2
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
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.
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
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.
Which of the following would be examples of derived demand?
1. A school hiring more teachers because the school's enrollment increased.
II. More people working at the movie theatre on Friday night because attendance increased.
III. More construction workers are needed because more people can afford to buy a new house.
O I and II only
o I and III only
Il and Ill only
O I, II and III
Answer:
The last one
Explanation:
on the exam
Among the following the derived demands are options 1 and 3 only. Because in each case, the demand for one thing is originated by the demand for another.
What is derived demand?The phrase derived demand in economics refers to the demand for a factor of production or intermediate good that results from the demand for another intermediate or final good. In essence, consumer demand for the firm's product determines how much a firm will need.
Additionally, if activity in one area rises, any sector that contributed to the success of the first sector may also experience growth. Here, the school is hiring more teachers because enrollment is increased. Thus, enrolling more teachers satisfies the demand by greater enrollments.
Similarly by recruiting more construction workers the increased demand for new house by people can be solved. However, the second case for filling the attendance is a necessary and not a derived demand.
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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 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