Answer:
12.72 sec
Explanation:
The time it takes to travel a certain distance can be found by dividing the distance that needs to be travelled by the speed with which you are travelling, therefore...
[tex]Time = \frac{Distance}{Speed} = \frac{318}{25} = 12.72 sec[/tex]
1. A small light bulb is shining light on a basketball (diameter is 23 cm or 9 inches). The light bulb is 3 m from the closest side of the basketball. Behind the basketball, on the side away from the light bulb, is a wall 4 m from the basketball. Calculate the size (diameter) of the basketball's shadow on the wall
Answer:
The size (diameter) of the basketball's shadow on the wall is approximately 53.38 cm
Explanation:
The given parameters of the basketball are;
The diameter of the basketball = 23 cm (9 inches)
The distance of the light bulb from the closest side of the basketball = 3 m
The distance from the ball to the wall = 4 m
The distance from the light source to the center of the ball, d = 3 m + 0.23/2 m = 3.115 m
The angle the light ray makes with the edge of the ball, θ = arctan(0.115/3.115)
Therefore, the ratio of the shadow width divided by 2 to the distance from the light from the wall = 0.115/3.115
The distance from the light from the wall = 3 m + 4 m + 0.23 m = 7.23 m
Therefore;
((The width of the shadow)/2)/(The distance from the light from the wall) = 0.115/3.115
∴ ((The width of the shadow)/2)/(7.23 m) = 0.115/3.115
((The width of the shadow)/2) = 7.23 m × 0.115/3.115 = 16629/62300 m ≈ 0.2669 m = 26.69 cm
The width (diameter) of the shadow on the wall = 2 × 16629/62300 m ≈ 0.5338 m = 53.38 cm
The size (diameter) of the basketball's shadow on the wall ≈ 53.38 cm
A man works on a striaght road from his home to market 2.5km away dwith a speed of 5km/h.Finding the market closed, he instantly truns and walk back home with a speed of 7.5km/h. The average speed of the man over the interval of time 0.40min.Is equal to?
Answer:
5.625km/h
Explanation:
We are given that
Distance between home and market, d=2.5 km
Speed, v1=5km/h
Speed, v2=7.5 km/h
We have to find the average speed of the man over the interval of time 0 to 40min.
Time,[tex]t=\frac{distance}{speed}[/tex]
Using the formula
[tex]t_1=\frac{2.5}{5}=0.5 h=0.5\times 60=30 min[/tex]
1 hour =60 min
[tex]t_2=\frac{2.5}{7.5}=\frac{1}{3}hour=\frac{60}{3}=20min[/tex]
Distance traveled by man in 10 min with speed 7.5 km/h=[tex]\frac{2.5}{20}\times 10=2.5/2km[/tex]
Therefore,
Total distance covered=2.5+2.5/2=3.75 km
Time=40 min=40/60=2/3 hour
Average speed=[tex]\frac{total\;distance}{total\;time}[/tex]
Average speed=[tex]\frac{3.75}{2/3}=5.625km/h[/tex]
Define one metre length.
Answer:
The metre is currently defined as the length of the path travelled by light in a vacuum in 1299 792 458 of a second
Fred is conducting a controlled experiment to test whether using a grow light at night will help a tomato plant grow faster. Below are the steps to Fred's experiment: Plant tomato plants in two separate, but identical, flowerpots. Place the flowerpots in the same area outside during the day. At night, bring both flower pots inside and place one in the dark and one under a grow light. Give the plants the same amount of food and water each week. Measure the growth of the plants. Draw conclusions based on the data collected. Which of the following variables must Fred hold constant in this experiment?
Answer:
the type of tomato plants used.
Explanation:
If magnet A can hold 3 steel paperclips and magnet B can hold 5 steel paperclips, which one is stronger
A: magnet A
B: magnet B
• C: they are equally strong
D: magnets wouldn't attract steel
paper clips
Answer:
magnet b
Explanation:
because it has a stronger current so it attracts more paper clips
A transverse wave has a frequency of 200 Hz with a wavelength of 1.0 m. Determine the speed
of the wave.
Answer:
200 m\ s Ans .....
Explanation:
Data:
f = 200 Hz
w = 1.0 m
v = ?
Formula:
v = f w
Solution:
v = ( 200)(1.0)
v = 200 m\s Ans .........
The particles of an ice cube at 0°C (represented by the blue circles) come in contact with the particles of Juan’s hand at 37°C (represented by the orange circles). Which diagram correctly represents the temperature of the two substances and the direction of heat flow?
Answer:
its b
Explanation:
The diagram which correctly represents the temperature of the two substances and the direction of heat flow is shown below.
What is heat?Heat is also referred to as thermal energy and it can be defined as a form of energy that is transferred from one physical object to another, especially as a result of a difference in temperature.
During the process of heat conduction, heat is primarily transferred between objects with different degrees of temperature and materials that are directly in contact with each other.
In conclusion, heat is generally transferred from a hotter object (37°C represented by the orange circles) to a cooler object (0°C represented by the blue circles) as shown in the image attached below.
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5. A student is investigating the relationship between pressure,
temperature, and entropy. A student manages to obtain a sample of ice,
water, and water vapor that all coexist at the same temperature called
the triple point. Which will have the greatest entropy at the triple point?
Answer:
The water vapor will have the greatest entropy at the triple point
Explanation:
At the triple point of water, which has the properties of 0.0075°C temperature and 6.11657 mbar pressure, solid ice, liquid water and water vapor exist together in a location
According to Professor Stephen Lower on LibreTexts website entropy is a measure the extent to which thermal energy is shared and spread in a system
The change in entropy, ΔS = ΔH/T
The heat change in [tex]\Delta H_{melting}[/tex] = 6.01 kJ/mol
The heat change in vaporization, [tex]\Delta H_{vaporization}[/tex] = 45.05 kJ/mol
The heat change in sublimation, [tex]\Delta H_{sublimation}[/tex] = 51.06 kJ/mol
Therefore, the entropy of the water vapor [tex]S_{water \ vapor}}[/tex] > The entropy of liquid water, [tex]S_{Liquid \ water}[/tex] > The entropy of the solid ice, [tex]S_{Solid \, ice}[/tex]
The portion with the highest entropy at the triple point is the water vapor
The water vapor will have the greatest entropy at the triple point
Which graph shows a vehicle traveling at a constant speed?
(look at the attached photo)
Which quantity is a vector?
А
acceleration
B.
distance
С
speed
D
mass
Answer:
b
Explanation:
Vector, in physics, a quantity that has both magnitude and direction.
If the wavelength of a wave in a particular medium is tripled, what will happen to the frequency of the wave?(1 point)
It will become one third of its original value.
It will depend on the speed of the wave.
It will become triple its original value.
It will remain constant.
Answer:
It will become one third of its original value
Explanation:
A 45-kg child sits on a 3.2-kg tire swing. What is the tension in the rope that hangs from a tree branch?
Answer:
472.36 N
Explanation:
The total mass with the tire and child would be 45 kg + 3.2 kg = 48.2 kg
Ft = force tension
Fg = force of gravity
Fnet=0 (because child is motionless and not accelerating)
0 = Ft - Fg
Ft = Fg
Ft = m*g
Ft = 48.2 kg * 9.8 m/s^2
Ft = 472.36 N
Hope this helps!!
A 45-kg child sits on a 3.2-kg tire swing. The tension of the rope is 472.36 N.
The parameters given in the question is
Mass of the child= 45 kg
Mass of the tire swing attached to the tree= 3.2 kg
What is Tension?Tension can be defined as the force that can gets transmitted through a rope, string or wire when they are pulled through any forces that should acting from opposite sides.The tension force can be directed throughout the length of the wire and also it pulls the energy equally on the bodies at the ends.All the physical object which will be in contact exerts some force on one another.The first step is to calculate the total mass. The total mass can be calculated as follows;
= Mass of the child + mass of the tire swing
= 45 + 3.2
= 48.2 kg
The tension can be calculated as follows,
= mass × acceleration
= 48.2 × 9.8
= 472.36
Hence, A 45-kg child sits on a 3.2-kg tire swing. The tension of the rope is 472.36 N.
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Why is visible light safe to humans ?
Explanation:
Visible light is the range of electromagnetic waves that humans can see. Anything that glows or gives off light makes waves of what we call visible light. The sun, light bulbs, candles and fire are all things that people automatically think of when it comes to light, but visible light comes from many sources and in many colors. Some other sources of visible light include: television and computer screens, glow sticks, and fireworks
Answer:
Visible light is visible because most of the gases in planetary atmospheres (oxygen, nitrogen, carbon dioxide, methane, ammonia…) are transparent to those wavelengths. We evolved to see those wavelengths because the atmosphere in visible light is transparent.
Explanation:
HELP AGAIN 10 POINTS
6. Compare Which of the
following can carry the
most current?
a. 9-V battery
b. 220-V electrical outlet
c. 12-V battery
d. 110-V electrical outlet
What is one difference between a total solar and a total lunar eclipse?
A: A solar eclipse happens once every 28 days. A lunar eclipse happens only during a full moon.
B: In a solar eclipse, the sun moves between Earth and the moon. In a lunar eclipse, the moon moves between the sun and Earth.
C: A solar eclipse can be viewed anywhere on Earth. A lunar eclipse can only be seen from the side of Earth facing the moon.
D: In a solar eclipse, it is Earth that is caught in the umbra of the moon. In a lunar eclipse, it is the moon that is caught in the umbra of Earth.
Answer:
Image result for What is one difference between a total solar and a total lunar eclipse?
During a total solar eclipse, the moon passes between Earth and the sun, casting a small, dark shadow on our planet. ... During a lunar eclipse, however, the Earth passes between the moon and the sun, casting its shadow — known as the umbra — onto the moon.
Answer:
D.
Explanation:
Which of the following is not a space rock?
A
a star
B
a comet
C
an asteroid
D
a meteoroid
Answer:
A
Explanation:
a star is a bolling gas so it not a space rock
A star is not a space rock. Thus, the correct answer is option A.
What is a star?A star is a type of astronomical object that consists of a luminous spheroid of plasma held together by gravity. The Sun is the closest star to Earth. Many other stars can be seen with the bare eyes at night, but due to their great distances from Earth, they appear as fixed points of light.
Many of the brightest stars have proper names, and the most prominent stars have been classified into constellations . As previously stated, a star is a massive self-luminous celestial body of gas that shines through radiation emitted by its internal energy sources. It is not a space rock.
Therefore, a star, which is self-luminous celestial body made up of gas, is not a space rock.
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PLS ANSWER FAST WILL GIVE BRAINLY!!!
what is an electron shell
Answer:
In chemistry and atomic physics, an electron shell may be thought of as an orbit followed by electrons around an atom's nucleus. The closest shell to the nucleus is called the "1 shell", followed by the "2 shell", then the "3 shell", and so on farther and farther from the nucleus.
Explanation:
Answer:
An electron shell is the outside part of an atom around the atomic nucleus. It is a group of atomic orbitals with the same value of the principal quantum number n
Explanation:
What is the period of a wave with a wavelength of 8 cm and a frequency of 0.5 hertz?(1 point)
0.125 seconds
2 seconds
4 seconds
0.0625 seconds
Answer:2 seconds
Explanation:
A spring has a spring constant of 90N/m.How much potential energy does it store when stretched by 2 cm?
Answer:
The potential energy stored in the spring is 0.018 J.
Explanation:
Given;
spring constant, k = 90 N/m
extension of the spring, x = 2 cm = 0.02 m
The potential energy stored in the spring is calculated as;
U = ¹/₂kx²
where;
U is the potential energy stored in the spring
Substitute the given values in the equation above;
U = ¹/₂ x 90 N/m x (0.02 m)²
U = 0.018 J
Therefore, the potential energy stored in the spring is 0.018 J.
Which of the following properties of a wave cannot be changed by reducing wave velocity?
A. Period
B. Frequency
C. Wavelength
D. Amplitude
Answer:
B
Explanation:
Trust me
Wavelength is the only one that CAN be.
A, B, or D can't be.
The cooling system of an automobile motor contains 20.0 kg of water. What is the Δt of the water if the engine operates until 836,000 J of heat have been added to the water?
Answer: 10 c
Explanation:
The cooling system of an automobile motor contains 20 kg of water, then the temperature change of the water is 10 °C.
What is heat?Heat is the result of the movement of kinetic energy from one substance or item to another, or from an energy source to a substance or object. Radiation, conduction, and convection are three different ways that this energy can be transferred.
The calorie (cal), the primary unit of heat in the International System of Units (SI), is the quantity of energy transfer necessary to raise the temperature of one gram of liquid from water by one degree's Centigrade, provided that the water's temperature is both higher than the freezing point and lesser than the boiling point.
The given data in the question is,
Heat, Q = 836000 J
Volume, V = 20 L
Mass, m = 20 kg
ΔT = Q/m[tex]C_p[/tex]
ΔT = (836000)/(20 × 4180)
ΔT = 10 °C
Therefore, the change in temperature will be equal to 10 °C.
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A small-motorized cart can go from a standing start to 42 m/s in 7 seconds. What is the acceleration rate of the cart?
A bus of mass 3,500 kg that is moving at a speed of 18 m/s and
a car of mass 1,300 kg that is moving at a speed of 20 m/s.
What's the total linear momentum of the bus and the car?
According to the given statement The total linear momentum of the bus and the car 890000 Kg • m/s.
What is a momentum in physics?Momentum be defined as the intensity of a body's motion. As momentum depends on both velocity and the orientation of the skin's motion, it is quantified by "mass velocity". Since speed is a vector and mass is a scalar, momentum is the product. Momentum propels you through from the finish line after helping you get beyond the initial difficulty of being unable to begin. Gaining momentum will enable you to go closer to your objectives by fostering optimistic thinking and energy.
How does momentum start?In Newtonian mechanics, an object's mass and velocity are combined to form momentum, more precisely linear energy or translational momentum. It has both a magnitude and direction, making it a vector quantity.
Briefing:P₁ = 3,500 kg
P₂ = 18 m/s
m₁ = 1,300 kg
V₁ = 20 m/s.
P₁ + P₂ = m₁V₁ + m₂V₂
3500(18) + 1300(20)
=63000 + 26000
=890000 Kg • m/s
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What is the Kinetic Energy of a 120 kg object that is moving with a velocity of 15 m/s
Answer:
Kinetic Energy:120 x 15=1800
Explanation:
Answer:
13500J
Explanation:
Kinetic energy = (1/2×120)kg × (15m/s)^2
KE = 60kg × 225 (m/s)^2 = 13500J
A 3.8-mole sample of an ideal gas is gently heated at a constant temperature of 340 K. The gas expands to 2.3 times its initial volume. What is the change in the internal energy of the gas? Let the ideal-gas constant R=8.314 (mol x K)
Answer:
0J
Explanation:
0J just took the test
examples of non viscous liquid
The fluids that have no resistance or zero resistance to internal friction are known as non- viscous fluids. • The fluid which has more resistance to flow is called viscous fluid. Viscosity is a property of a fluid, which is a degree of the amount of resistance between the fluid layers.
WILL GIVE YOU BRAINLIST IF YOU ANSWER
Arctic foxes have adapted to the tundra cycles by turning white in the wintertime. Which other tundra animal has adapted the same way?
musk oxen
willow ptarmigan
black flies become white flies
grey wolf
Answer:
thanks
Explanation:
willow ptarmigan
Your are on a boat on a lake with no current. The lake is full of sharks that will eat you if you put your hands too close to the water, and your paddle has been eaten by those sharks. However, you do have a big bucket of grapefruit in the boat. How will you get to shore? Your answer must reference Newton's third law.
Answer:
i would use the grapefruit and throw it into the water 1 by 1 one leaving sometime in between to see the sharks reaction to it. If they get attracted to it i would throw 1 in then use the bucket to push foward as fast as i can with all of my strength so i can get an equal and opposite reaction from the water to push me foward, i would keep this up for as long as i can. The size of the bucket and the amount of grapefruit were never specified so i would use this for my benefit to say its enough to get to shore
Explanation:
SOMEONE HELP ME PLEASE
Free is the movement of an object towards earth solely because of gravity.
What is freefall? Free fall is when objects falling near earth’s surface accelerate downward at rate of 9.8 m/s2.
Give an example of an object in free fall
