Complete Question
A child throws a ball with an initial speed of 8.00 at an angle of 40.0° above the horizontal. The ball leaves her hand 1.00 m above the ground and experience negligible air resistance. (a) What is the magnitude of the ball's velocity just before it hits the ground? (b) At what angle below the horizontal does the ball approach the ground?
Answer:
[tex]v=9.16m/s[/tex]
[tex]\theta=48.1 \textdegree[/tex]
Explanation:
From the question we are told that
Angle of ball [tex]\angle=40 \textdegree[/tex]
Height of ball h=1m
Generally the equation for vertical component is mathematically given by
[tex]v_y=vsin \theta[/tex]
[tex]v_y=8sin 40 \textdegree[/tex]
[tex]v_y=5.14m/s[/tex]
Generally the equation for horizontal component is mathematically given by
[tex]v_x=vcos \theta[/tex]
[tex]v_x=8cos 40 \textdegree[/tex]
[tex]v_x=6.12m/s[/tex]
Generally the equation for vertical displacement of ball is mathematically given by
[tex]y=1+v-yt-\frac{1}{2}gt^2[/tex]
[tex]0=1+5.14t-\frac{1}{2}*9.87*t^2[/tex]
[tex]t=1.22sec[/tex]
[tex]v_yt=v_yt-gt[/tex]
[tex]5.14-(9.8*1.22)=-6.816m/s[/tex]
[tex]v_yt=-6.816m/s[/tex]
Generally the velocity of ball before it hits the ground is mathematically given by
Magnitude
[tex]v=\sqrt{6.12^2 +(-6.816)^2}\\[/tex]
[tex]v=9.16m/s[/tex]
Direction of ball
[tex]\theta=tan^{-1}(\frac{-6.816}{6.12} )[/tex]
[tex]\theta=48.1 \textdegree[/tex] beneath the horizontal
Friction produces heat because it causes molecules to move faster and
have more energy.
True or false.
Answer:
True
Explanation:
Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye make look rough or bumpy when viewed under a microscope. You know that friction produces heat. That’s why rubbing your hands together makes them warmer. But do you know why? Friction causes the molecules on rubbing surfaces to move faster, so they have more energy. This gives them a higher temperature, and they feel warmer. Heat from friction can be useful. It not only warms your hands.
A 2.70 kg book rests on an incline of 13.0. You give it a sharp push up the frictionless ramp. It comes to a stop in 25.25 at 17.5 m up the ramp before starting its descent(a) What is the magnitude of the normal force on the book
Answer:
the magnitude of the normal force on the book is 25.78N
Explanation:
The computation of the magnitude of the normal force on the book is shown below
Normal force = N is
= mgcosβ
= 2.70 × 9.8 × cos13°
= 25.78N
hence, the magnitude of the normal force on the book is 25.78N
The above formula should be applied
Which statement can be supported by using a position-time grap
O A negative slope results when an individual is moving away
O A horizontal line on the graph means the individual is moving
O A positive slope results when an individual is moving away fr
O The speed of an individual cannot be determined from this ty
Answer:
A negative slope results when an individual is moving away
Explanation:
Which of the following has the most kinetic energy?
A.
A car traveling at 80 kph.
B.
A tractor trailer traveling at 80 kph.
C.
A cheetah running at 80 kph.
D.
A notorcycle traveling at 80 kph.
Answer:
B
Explanation:
A tractor is the heaviest
An ice skater of mass 82 kilograms stands at rest in her skates on the ice rink. Someone throws a 5-kg ball at her at a speed of 17.4 m/s and she catches it. At what speed will she(and the ball) slide backwards?
Answer:
1 m/s
Explanation:
I showed my work in the picture attached.
This web page helped me solve this problem and understand inelastic collisions a little better:
https://byjus.com/physics/inelastic-collision/
She slide(and the ball) backwards at the speed of 1m/s when she catches the ball of 5-kg coming at speed of 17.4 m/s.
What is momentum ?Momentum is defined as mass times velocity. it tells about the moment of the body. it is denoted by p and expressed in kg.m/s. mathematically it is written as p = mv. A body having zero velocity or zero mass has zero momentum. its dimensions is [M¹ L¹ T⁻¹].
Momentum is conserved throughout the motion.
According to conservation law of momentum initial momentum is equal to final momentum.
Given,
mass of the skater m₁ = 82 kg
mass of the ball m₂ = 5kg
initial velocity of the ball v'₂ = 17.4 m/s
initial velocity of the skater v''₂= v'₁= 0
final velocity of the ball & skater = v''₁ = ?
According to law of conservation of momentum,
initial momentum = final momentum
m₁v'₁ +m₂v'₂ = m₁v₁'' + m₂v''₂
putting all values in the equation.
0+ 5×17.4 = 82×v₁'' + 5×v₁''
v₁''(82+5) = 87
v₁'' = 1 m/s
Hence he(and the ball) slide backwards at 1m/s
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Problem 3 (a) Assuming the human body (skin temperature 34◦C) to behave like an ideal thermal radiator, find the wavelength where the intensity from the body is a maximum. In what region of the electromagnetic spectrum is radiation with this wavelength? (b) Making whatever (reasonable) assumptions you may need, estimate the power radiated by a typical person isolated from the surroundings. (c) Estimate the radiation power absorbed by a person in a room in which the temperature is 20◦C.
Answer:
Explanation:
a )
We shall apply Wein's displacement law
λm x T = b where λm is wavelength of radiation having maximum intensity
T is absolute temperature of body , and b is a constant
b = 2898 μm-K
T = 273 + 34 = 307 K
λm x 307 = 2898
λm = 9.44 μm
= 9440 nm
It is infrared radiation .
b )
We shall apply Stefan's law of radiation.
E = σA T⁴
E is emitted radiation by body acting as black body , A is surface area , T is absolute temperature of body
σ = 5.67 x 10⁻⁸ J / m²T⁴
Surface area of a typical man's body A = 1.9 m²
T = 273 + 34 = 307 K
Assuming human body as black body
E = 5.67 x 10⁻⁸ x 1.9 x 307⁴ J/s
= 9.57 x 10² J/s
= 957 W .
c )
Radiation absorbed
E = 5.67 x 10⁻⁸ x 1.9 x ( 273 + 20 )⁴ J/s
= 794 W .
Explain what happens with the 0.25 days each year
Answer:
leap year
Explanation:
A volleyball player spiking is it kinetic or potential
Answer:
It is kinetic energy.
Explanation:
The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate the volleyball from rest to its stated velocity. Having gained this energy from the player spiking it during its acceleration, the body maintains this kinetic energy unless its speed changes.
Has anyone has the answers for Physical Education # 12 cross word and the word search?
Answer:
No
Explanation:
the answers, they seemed to be blocked on go.ogle
A 20.0 newton force is used to push a 2.00 kilogram cart a distance of 5.00 meters how much work is done on the cart
Answer:
100
w=f*s
20*5=100....
100 Joules of work is done on the cart.
What is Work done?Work done by a force is defined as the product of the displacement and the component of the applied force on the object in the direction of displacement. When we push a block with some force, the body moves with some acceleration, so it is called work done.
Work done is expressed as W=Fd and its unit is joules which can be defined as the amount of work done by a force in Newton is applied to an object, as a result of which it is displaced in meter.
For above given information,
Force= 20 N
Distance= 5 m
So, work done= 20*5= 100 Joules
Thus, 100 Joules of work is done on the cart.
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Shine the flashlight on the liquid sheet. Did you observe evidence that light carries energy
Answer:
Think of an object you have observed ... Work with your group to gather evidence that light carries energy, then answer the questions below. Shine the flashlight on the liquid crystal sheet.
What is the frequency of a wave that has a wavelength of 0.20 m and a speed of 22 m/s
Answer:
The frequency of the wave would come out to be 110 Hz.
Frequency is the number of completed wave cycles per second. By using the simplest frequency equation, f = 1 / T, you get the answer I provided above.
An object is traveling with a constant speed of 35 m/s. How long does it take to cover 770 m?
Answer:
22 s
Explanation:
time = distance / velocity
We know that distance = 770 m and velocity = 35 m/s.
t = d / v
t = 770 m / 35 m/s
t = 22 s
It takes 22 seconds to cover 770 m. Hope this helps, thank you !!
what is a likely consequence of continued human population growth
Answer:
Rapid human population growth has a number of consequences. Population grows fastest in the world's poorest countries. High fertility rates have historically had a strong relation with poverty, and high childhood mortality rates
Explanation:
i got it from goo.gle but i hope that helps:)
have a good day bro
flint glass materials
Answer:
Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
:)
Answer:Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
What happens to the electrons when you rub a balloon in your hair
Answer:
When you rub a balloon on your head, electrons move from the atoms and molecules in your hair onto the balloon. Electrons have a negative charge, so the balloon becomes negatively charged, and your hair is left with a positive charge.
Explanation:
The bus is heading southwest at 56 miles per hour is it veloctiy or speed
Answer:
Its velocity
Explanation:
Velocity is speed with a direction.
Speed is the rate at which someone or something is able to move or operate.
In the question its telling us that the bus is going 56 miles per hour but it aslo gives us a direction, in this case is southwest.
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. How long after leaving the first station did the train arrive at the second station?
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
What is speed?The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
time = Distance / speed
= 63/35.
= 1.8 sec
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
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How much time will it take for a bug to travel 2 meters across the floor if it is traveling at 0.5 m/s?
Need help guys please
Answer:
c is the answer,................
(b) The efficiency of the pump which operates the fountain is 70%.
Calculate the power supplied to the pump.
Answer:
Power supplied to the pump is 980000 W or 980 KW
Note: The question is incomplete. The complete question is given below:
On a day with no wind, a fountain in Switzerland propels 30000 kg of water per minute to a height of 140 metres.
a)Calculate the power used in raising the water?
b)The efficiency of the pump which operates the fountain is 70%
calculate the power supplied to the pump?
Explanation:
Efficiency = Power output/Power input * 100%
Power output = work done/ time
where work done = mass * acceleration due to gravity (g) * height
time = 1 minute = 60 seconds
mass of water = 30000 kg, height = 140 meters, g = 9.8 m/s²
Then, work done = 30000 * 140 * 9.8 = 41160000 J
Power output then = 41160000 J / 60 s
Power output = 686000 W
The power input can then be derived from the formula of efficiency
Power input = (Power output * 100)/Efficiency
Power input = (100 * 686000) / 70
Power input = 980000 W
Therefore, power supplied to the pump is 980000 W or 980 KW
Similarities between football and badminton ?
Answer:
Explanation:
Football and badminton enquire you use your lems and you would need equipment
Football and badminton enquire you use your legs and you would need equipment.
What are the similarities between badminton and tennis?Similarities of Tennis & Badminton both are racket sports. both video games consist of a net in which the ball/shuttlecock needs to be hit over the internet to the opponent's court which will win the point. Both video games have guys singles, guys doubles, girls singles, girls doubles, and combined doubles categories.
Each game and sports activities have hard and fast policies, which ensure honest opposition. they may involve teams or individual competitions. Human beings play video games and sports for activity and amusement, but in addition, they benefit from numerous skills and understanding via video games and sports activities.
While soccer is played through feet, handball is a game played by using hand. Both sports have some similarities which consist of the function of the goalkeeper who can play with ft and arms in the strive of saving the ball from attaining the purpose.
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What energy transfer happens in many musical instruments?
Sound to kinetic
Electrical to kinetic
Kinetic to sound
Answer:
kinetic to sound
Explanation:
this is because energy is moving in the instrument and it produces sound.
If you started counting from 1st grade, how many years of education would the typical professional astronomer have today, at minimum?
12
14
16
18
16 years of education would the typical professional astronomer have today, at minimum
what are the basic qualification needed for astronomer ?Minimum qualifications of Astronomer 4 year degree to get a postgraduate qualification like a master of physics.
2 or 3 A levels of math and physics; 5 GCSEs at grades 9 to 4 (A* to C), or equivalent; and a degree in a field that is useful for postgraduate are needed.
Math and physics expertise needed, analytical thinking abilities, science knowledge, great verbal communication skills, and the capacity to think coherently both logic and reasoning are all essential.
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To attain the maximum range a projectile has to be launched at 45 degrees if the landing spot and the launch spot are at the same height (neglecting air resistance effects.) Explain in a few sentences how the relation between the vertical and the horizontal components of the initial velocity affects the projectile range
Answer:
see that the velocities are the components in a Cartesian system
Explanation:
The horizontal velocity of the projectile is the x-axis component of the initial velocity
v₀ₓ = v₀ cos 45
vertical speed is
[tex]v_{oy}[/tex] = v₀ sin 45
therefore we see that the velocities are the components in a Cartesian system
3. It takes at least 4 people to push a refrigerator up a 10-meter ramp. How many people would be needed to push the same refrigerator to the same height using a
20-meter ramp? (Assume no friction for both ramps.)
O A. at least 2 people
O B. at least 4 people
O c. at least 8 people
D. Not enough information (could be impossible).
.
Answer:
A
Explanation: Using a ramp that is twice is long (and therefore flatter) means that half as much force is needed. Force is provided by the people who push, so only half as many people would be needed.
At least 2 people would be needed to push the same refrigerator to the same height using a 20-meter ramp.
Given the following data:
Number of people = 4 people.Height A = 10 meters.Height B = 20 meters.What is a ramp?A ramp can be defined as a sloping plane or surface that is typically used to connect two (2) levels; a higher and a lower level.
In this scenario, a ramp that is twice as long as the first ramp was used to push a refrigerator up. This simply means that, half the magnitude of force provided by the 4 people pushing the refrigerator up a 10-meter ramp would be needed for the 20-meter ramp, assuming no friction for both ramps.
In conclusion, we can deduce that at least 2 people would be needed to push the same refrigerator to the same height using a 20-meter ramp.
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A parcel has a mass of 500 g .calculate its weight (assume the gravitational field strength is 10 N/Kg
Answer:
5N
Explanation
convert grams to kg and multipy with 10 (.5 *10)=5N
Calculate the amount of potential difference in a capacitor of 0.9 MF , If the amount of charge is 1.4x10^-4 C .(Show all the work)
Answer:
Potential difference [tex]V=1.6\times 10^{-10}\ V[/tex]
Explanation:
Capacitance of capacitor, C = 0.9 MF
Charge, [tex]Q=1.4\times 10^{-4}\ C[/tex]
We need to find the amount of potential difference. We know that,
[tex]Q=CV[/tex]
V is potential difference
So,
[tex]V=\dfrac{Q}{C}\\\\V=\dfrac{1.4\times 10^{-4}}{0.9\times 10^6}\\\\V=1.6\times 10^{-10}\ V[/tex]
So, the required potential difference is [tex]1.6\times 10^{-10}\ V[/tex].
Could I please get some help on this question I don’t understand .
Answer:
12.5 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Height (h) = 8 m
Final velocity (v) at 8 m above the lowest point =?
NOTE: Acceleration due to gravity (g) = 9.8 m/s²
The velocity of the roller coaster at 8 m above the lowest point can be obtained as follow:
v² = u² + 2gh
v² = 0² + (2 × 9.8 × 8)
v² = 0 + 156.8
v² = 156.8
Take the square root of both side
v = √156.8
v = 12.5 m/s
Therefore, the velocity of the roller coaster at 8 m above the lowest point is 12.5 m/s.
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