The initial velocity of the projectile is 19.8m/s
Explanation:
First, find time.
From our kinematics equations:
delta y = Vi•t + (1/2)at^2
rearrange,
t = sqrt[(2•delta y)/a]
t = sqrt[(2•20m)/9.8m/s^2]
t = 2.02s
Next, plug time into new kinematics equation to solve for the Vi in the x direction (horizontal)
delta x = Vi•t + (1/2)at^2
delta x = Vi•t
Rearrange:
Vi = delta x/t
Vi = 40m/2.02s
Vix = 19.8m/s
Consult Multiple-Concept Example 5 to review the concepts on which this problem depends. A light bulb emits light uniformly in all directions. The average emitted power is 150.0 W. At a distance of 6 m from the bulb, determine (a) the average intensity of the light, (b) the rms value of the electric field, and (c) the peak value of the electric field.
Answer:
a. 0.332 W/m² b. 11.2 V/m c. 15.8 V/m
Explanation:
(a) the average intensity of the light,
Intensity, I = P/A where P = average power = 150.0 W and A = area through which the power emits = 4πr² where r = distance from bulb = 6 m.
So, I = P/A = P/4πr²
Substituting the values of the variables into the equation, we have
I = P/4πr²
I = 150.0 W/4π(6 m)²
I = 150.0 W/4π(36 m²)
I = 150.0 W/452.39 m²
I = 0.332 W/m²
(b) the rms value of the electric field,
Since Intensity, I = E²/cμ₀ where E = rms value of electric field, c = speed of light = 3 × 10⁸ m/s and μ₀ = permeability of free space = 4π × 10⁻⁷ H/m.
Making E subject of the formula, we have
E² = Icμ₀
E = √(Icμ₀)
Since I = 0.332 W/m², substituting the other terms into the equation, we have
E = √(0.332 W/m² × 3 × 10⁸ m/s × 4π × 10⁻⁷ H/m.)
E = √(0.332 W/m² × 3 × 10⁸ m/s × 4π × 10⁻⁷ H/m.)
E = √(12.5 × 10)
E = √125 V/m
E = 11.18 V/m
E ≅ 11.2 V/m
(c) the peak value of the electric field.
The peak value of electric field, E' is gotten from E = E'/√2 where E = rms value of electric field.
So, E' = √2E
= √2 × 11.2 V/m
= 15.81 V/m
≅ 15.8 V/m
____ is based on the acceptance of rules and laws.
Multiple Choice
1. Rational-legal authority
2. Traditional authority
3. Legal power
4. Political power
three small balls each of mass 13.3g are suspended separately from a common point by silk threads, each 1.17m long. The balls are identically charged hang at the corners of equilateral triangle 15.3 cm on a side. Find the charge on each ball
The charge on each ball is 6.1 ×10⁻⁸ C.
What is force?The definition of force in physics is: The push or pull on a massed object changes its velocity.
An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. A spring balance can be used to calculate the Force. The Newton is the SI unit of force. Force is a vector quantity and it has both magnitude and direction.
Let the balls have equal charge of q. Then, electrostatic force acting on each particle = √3 q²/r² dyne = √3 q²/15² dyne =0.0076 q².
Weight of each ball = 13.3 ×980 dyne = 13034 dyne.
As the electrostatic force and the weight acts perpendicular to each other.
Hence, 0.1/√3 = 0.0076 q²/13034
q = 6.1 ×10⁻⁸ C
Hence, the charge on each ball is 6.1 ×10⁻⁸ C.
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You are a member of an alpine rescue team and must get a box of supplies, with mass 3 kg , up an incline of constant slope angle 30.0, so that it reaches a stranded skier who is a vertical distance 4 m above the bottom of the incline. There is some friction present; the kinetic coefficient of friction is 0.05. Since you can't walk up the incline, you give the box a push that gives it an initial velocity; then the box slides up the incline, slowing down under the forces of friction and gravity. Take acceleration due to gravity to be 9.81 m/s2 .What is the minimum speed v that you must give the box at the bottom of the incline so that it will reach the skier
Answer:
v = 9.04 m / s
Explanation:
For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.
W = Em_f - Em₀ (1)
Starting point. Lower slope
Em₀ = K = ½ m v²
highest point. Where is the skier at a height h
Em_f = U = m g h
The work of rubbing
W = -fr x
the negative sign is because the friction force opposes the movement.
Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular
let's use trigonometry to break down the weight
cos θ = W_y / W
sin θ = Wₓ / W
W_y = W cos θ
Wₓ = W sin θ
Y axis
N - Wₓ = 0
N = mg sin θ
X axis
fr = m a
the friction force has the expression
fr = μ N
fr = μ mg sin θ
we look for the job
W = - μ mg sin θ x
where x is the distance along the slope
we substitute in 1
-μ mg sin θ x = mg h - ½ m v²
let's use trigonometry to find the distance x
tan 30 = h / x
x = h / tan 30
we substitute
- [tex]\mu \ mg \ sin \theta \ \frac{h}{tan 30} \ x[/tex] = m gh - ½ m v²
we use
tan 30 = sin30 / cos30
v² = 2g h + 2 μ g h cos 30
v = [tex]\sqrt{ 2gh \ (1+ cos 30}[/tex]
let's calculate
v = [tex]\sqrt{ 2 \ 9.8 \ 4 \ (1 + 0.05 \ cos \ 30)}[/tex]
v = 9.04 m / s
Which statement explains how a chemical reaction depends on collisions
between molecules?
A. The reactants must collide in a certain way for the reaction to
occur.
B. The reaction will occur if the reactants collide in anyway.
C. The reaction will occur if the product collide in anyway.
D. The product must collide in a certain way for the reaction to occur
Answer: A. The reactants must collide in a certain way for the reaction to occur.
Explanation: I did the quiz :)
Answer:
A) The reactants must collide in a certain way for the reaction to
occur.
Explanation:
A.P.E.X
I need help! thank you
Answer:
it is coice A and choice D
What happens during
convection?
A. Heat is transferred from warmer
objects to cooler objects by direct contact.
B. Heat is transferred from warmer
objects to cooler objects by moving fluids.
C. Heat is transferred from warmer
objects to cooler objects through empty
space.
Answer:
B
Explanation:
four examples of compounds which are classed as carbohydrate
Answer:
Carbohydrates are divided into four types: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides consist of a simple sugar; that is, they have the chemical formula C 6 H 12 O 6. Disaccharides are two simple sugars. Oligosaccharides are three to six monosaccharide units, and polysaccharides are more than six.
While being thrown, a net force of 132 N acts on a baseball (mass = 140g) for a period of 4.5 x 10^-2 sec. what is the magnitude of the change in momentum of the ball?
Answer:
5.94 N·s
Explanation:
F = 132 N
t = 0.045 s
Impulse = Ft = (132 N)(0.045 s) = 5.94 N·s
ANSWER THIS! Which of these statements about the Sun is the result of its closeness to Earth? A) It is the only star with a gravitational pull. B) It is the largest star in the Milky Way Galaxy. C) It appears (from Earth) to be the brightest star. D) It has the lowest temperature of any star seen from Earth.
Answer:
C) It appears (from Earth) to be the brightest star.
Explanation:
This is because due to sun's brightness we can predict its distance.
Which of the following statements about social connections today is most accurate?
Multiple Choice
1 People today are less socially connected than in past generations.
2. There is good cause for concern that technology will create social isolation.
3. The structure of friendship-how we connect and with whom-is changing
4. The nature of friendship is the same as in the past, but technology creates more social disconnection
Answer:
is point 2
Explanation:
There is a good cause for concern that technology will create social isolation
Three resistors: R1 = 5 Ω,R2 = 3 Ω, and R3 = 4 Ω are connected in series to each other. A voltmeter connected in parallel to resistor R2 measures voltage of 6 V. What is the current through the battery?
Answer: current I= 2 A
Explanation: when resistors are in series current I is same
Through each resistor. Potential drop along resistor R is
ΔV= IR. then I = ΔV/R = 6V/3Ω
Three resistors: R1 = 5 Ω,R2 = 3 Ω, and R3 = 4 Ω are connected in series to each other. A voltmeter connected in parallel to resistor R2 measures a voltage of 6 Volts, then the current flowing through the battery would be 2 Ampere.
What is resistance?Resistance is the obstruction of electrons in an electrically conducting material.
As given in the problem ,Three resistors: R1 = 5 Ω,R2 = 3 Ω, and R3 = 4 Ω are connected in series to each other. A voltmeter connected in parallel to resistor R2 measures a voltage of 6 V.
By using Ohm's Law,
V = IR
6 Volt = Electric current × 3 Ohms
Electric current = 6 volt / 3 Ohm's
= 2 Ampere
Thus, the current flowing through the battery would be 2 Ampere.
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A 1500 kg car traveling at 30 m/s hits a stationary 1200 kg car. If they stick together on collision, what is the final velocity of the two cars?
Answer:
16.67 m/s
Explanation:
Let that velocity be v.
Using conservation of momentum:
Initial momentum = final momentum
momentum of car1 = momentum of cars
mass1 x velocity1 = (m1 + m2)v
1500*30 = (1500 + 1200)v
45000/2700 = v
16.67 m/s = v
Which letter represents the
South American Plate
Answer:
B
Explanation:
Where it shows on the map is B
Key Stage 3 Science - Physics
Question 19 of 35
Calculate the force applied in newtons) if a pressure of 150Pa is acting on an area of 25m².
Answer:
F = 3750 N
Explanation:
Given that,
Pressure, P = 150 Pa
Area, a = 25m²
We need to find the force applied. We know that, pressure is equal to the force acting per unit area. It can be given by :
[tex]P=\dfrac{F}{A}\\\\F=P\times A\\\\F=150\ Pa\times 25\ m^2\\\\F=3750\ N[/tex]
So, the required force is 3750 N.
A force of 880 newtons stretches a spring 4 meters. A mass of 55 kilograms is attached to the end of the spring and is initially released from the equilibrium position with an upward velocity of 8 m/s. Find the equation of motion. x(t)
Answer:
x(t) = -8sin2t
Explanation:
See the attachment for solution
From my solving, we can deduce that w² = 4, and thus, w = 2
Therefore, the general solution is
x(t) = c1 cos2t + c2 sin2t
Considering the final variable, we can conclude that
x(0) = 0
x'(0) = -8 m/s
The final solution, thus
x(t) = -8sin2t
11
Y
What I Have Learned
Fill in the blanks with the correct word to complete each sentence.
Choose your answer inside the box and write it on your answer sheet.
more
sun
distance
gravitational force
less
moon
weightlessness
weightiness
mass
1. The greater the object's mass, the
gravity it exerts.
2. The greater the
or the shorter the
the stronger the
gravity is.
3. All objects are attracted toward the center of the earth due to
4. The
pulls the water from the oceans to make the tides.
5. The astronauts appear to float in space because of
inside the
spaceship.
Answer:
Where are the answer choices?
Explanation:
An astronomer studies an image taken by a satellite in space and sees an area of gas, dust, and many stars distributed along spiral arms. What is the astronomer most likely seeing?
Answer:the answer is galaxy
Explanation:
If the bar magnet on the left were broken in half, what statement correctly predicts how the two halves of the magnet would react
to the magnet on the right?
Answer:
According to the law of magnetism, "Like poles repel, unlike poles attract" If the bar magnet on the left is broken, both halves will consequently have two poles, the north and south poles. If the right sides of both halves are of the south pole, the bar magnet on the right is of the north pole
Calculate the size of the magnetic field 20 m below a high voltage power line. The line carries 450 MW at a voltage of 300,000 V. Group of answer choices 0.237 T 0.0237 T 0.474 T 2.37 T 0.237 J
Answer:
[tex]1.5 \times 10^{-5} \mathrm{~T}[/tex].
Explanation:
Power carried by the line [tex]=P=450 \mathrm{MW}=450 \times 10^{6} \mathrm{~W}[/tex]
Voltage across the line Volts
Current flowing in the line =i
Size of magnetic field =B
Distance from the line
Formula Used:
Current flowing is given as
[tex]i=\frac{P}{\Delta V}[/tex]
Magnetic field by the current carrying wire is given as
[tex]B=\left(\frac{\mu}{4 \pi}\right)\left(\frac{2 i}{r}\right)[/tex]
Inserting the values
[tex]B=\left(10^{-7}\right)\left(\frac{2(1500)}{(20)}\right) \\ B=1.5 \times 10^{-5} \mathrm{~T}[/tex]
Conclusion:
Thus, the magnetic field comes out to be [tex]1.5 \times 10^{-5} \mathrm{~T}[/tex].
Conductivity in aqueous solutions, is a measure of the ability of water to conduct an electric current.
a. True
b. False
Answer:
true
Explanation:
i think its true beacuse water can cause electricity
pls let me know if corrct
if yes pls mark brainlest
Determine experimentally which rotational axis yields the maximum rotational inertia (i.e., moment of inertia) and which yields the minimum rotational inertia for the broom stick. Draw a picture of the broom stick with its axis of rotation for (i) the minimum rotational inertia and (ii) the maximum rotational inertia.
Answer:
the maximum is I₁ axis of rotation at the end
the minimum moment is I₂ axis of rotation at the center of mass
Explanation:
For this exercise we use the definition moment of inertia
I = ∫ r² dm
for bodies of high symmetry it is tabulated; In this case we can approximate a broomstick to a thin rod, the moment of inertia with respect to a perpendicular axis when varying are
at one end
I₁ = ⅓ mL²
in in center
I₂ = [tex]\frac{1}{12}[/tex] m L²
There is another possible axis of rotation around the axis of the broom, in this case we have a solid cylinder
I₃ = [tex]\frac{1}{2}[/tex] m r²
remember that the diameter of the broom is much smaller than its length, therefore this moment of inertia is very small
when examining the different moments of inertia:
the maximum is I₁ axis of rotation at the end
the minimum moment is I₂ axis of rotation at the center of mass
A mountain climber, in the process of crossing between two cliffs by a rope, pauses to rest. She weighs 520 N. As the drawing shows, she is closer to the left cliff than to the right cliff, with the result that the tensions in the left and right sides of the rope are not the same. Find the tensions in the rope to the left and to the right of the mountain climber.
Answer:
The answer is "892.90 N"
Explanation:
Following are the solution to these question:
Calculating the vertical force of the summation that is equal to zero:
[tex]\to TL \cos 65 + TR \cos 80 -520 = 0\\\\\to 0.4226\ TL + 0.1736\ TR = 520\\[/tex]
Calculating the sum of horizontal forces that is equal to zero:
[tex]\to TL\sin 65 - TR \sin 80 = 0 \\\\\to 0.9063TL - 0.9846TR = 0\\\\\to TL = (\frac{0.9846}{0.9063})\ TR \ \ = 1.0866\ TR\\\\\to 0.4226(1.0866) \ TR +0.1736\ TR =520 \ N\\\\\to 0.6328 \ TR = 520 \\\\\to TR = 821.74 \ N \\\\\to TL = 1.0866 \times 821.74 = 892.90\ N[/tex]
If the distance doubles, what happens to the force?
a. Reduced by half
b. Reduced by 1/4
c. Stays the same
d. Quadruples
Katelyn (55 kg) is practicing a drop jump in the biomechanics lab. She steps off a plyometrics box, lands on the force plate, and immediately jumps back up into the air. Right before she hits the force plate, her vertical velocity is 3.0 m/s downwards. After leaving the ground again, her vertical velocity is 3.5 m/s upwards. Katelyn was in contact with the ground for 0.4 seconds. (a) What was the impulse exerted on Katelyn when she was on the force plate
Answer:
J = 357.5 kg*m/s
Explanation:
The impulse exerted on Katelyn when she was on the force plate, is equal to the change in her momentum, according to Newton's 2nd Law.Assuming as the positive direction the upward direction (coincident with the positive y-axis) we can express the initial momentum as follows:[tex]p_{o} = m*v_{o} = 55 kg * (-3.0 m/s) (1)[/tex]
By the same token, the final momentum is as follows:[tex]p_{f} = m*v_{f} = 55 kg * (3.5 m/s) (2)[/tex]
As we have already said, the impulse J is just equal to the change in momentum, i.e., the difference between (2) and (1):[tex]J = p_{f} - p_{o} = m* (v_{f} -v_{o}) = 55 kg* (3.5m/s- (-3.0m/s)) = 357.5 kg*m/s (3)[/tex]
What determines how powerful a magnet is?
Answer:
I would assume a force of gravitational pull.
Explanation:
Answer: How powerful the pull is or how many magnetic things it can pick up at one time, or a heavy magnetic object.
Explanation:
Using this formula a = F/m What acceleration results from exerting a 125N force on a 0.65kg
ball?
A. 182.3 m/s^2
B. 192.3 m/s^2
C. 192.7 m/s^2
D. 162.3 m/s^2
Answer:
Acceleration = 192.3 m/s² (Approx.)
Explanation:
Given:
Force = 125 N
Mass of ball = 0.65 kg
Find:
Acceleration
Computation:
We know that;
Acceleration = Force / Mas
So,
Acceleration = 125 / 0.65
Acceleration = 192.3 m/s² (Approx.)
A proton moves at a speed of 0.12 x 10^7 m/s
at right angles to a magnetic field with a
magnitude of 0.58 T.
Find the magnitude of the acceleration of
the proton. The elemental charge is 1.60 x
10^-19 C.
Answer in units of m/s?.
Answer:
13/23 ydfffgggggggffttf
PLZZZ HELP!!! 80PTS!!!
You are given a toy car and told it has a density of 0.54 g/mL and a volume of 38.2 mL. Calculate impulse, given that the toy car's acceleration is 10 m/s^2 and time is 10 s. WRITE THE NUMBER ONLY and DO NOT ROUND.
Answer:
Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s
Explanation:
Impulse is equal to the product of force and time
Here
Density of car = [tex]0.54[/tex] g/mL
Volume of car [tex]= 38.2[/tex] mL
Mass of the car is equal to the product of density and volume of car
Mass of the car [tex]= 0.54 * 38.2[/tex] [tex]= 20.628[/tex] grams
Acceleration of the car is [tex]10[/tex] m/s^2
Force is equal to product of mass and acceleration
F = [tex]20.628 * 10 = 206.28[/tex] g .m/s^2
Impulse = F * t
Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s
What holds the moon in orbit around the earth?
A. The sun's gravity
B. The Earth's gravity
Answer:
Earth's gravity
Explanation:
hope this helps
Answer:
the earth gravity
Explanation:
Gravitational attraction provides the centripetal force needed to keep planets in orbit around the Sun and all types of satellite in orbit around the Earth. The Earth's gravity keeps the Moon orbiting us.