Answer:
1. True
2. True
3. True
4. True
5. False
Explanation:
1. Indeed, many health experts often recommend that when children reach the age of adolescents (between ages 10 and 19) they should eat a variety of foods daily in other to have enough energy and nutrients needed for development.
2. Having regular meals (mornings, afternoon, and evenings) has for long been encouraged by medical professionals in other to provide the body its fuel.
3. Some skin problems have long been associated with too much consumption of sweets and desserts since these products often contain sugars, and excess processed sugar intake is said to increase acne and eczema.
4. Just as the name suggests, the food pyramid is a visual representation that contains how many servings from each food group in other be healthy.
5. This is false because throughout the growth stages of life it is essential to get the needed food nutrients such as calcium, iron, protein, and energy foods.
Question 5 of 10
When dim blue light shines on a piece of metal, electrons are ejected from its
surface, but not when bright red light shines on the metal. Does this
phenomenon provide evidence for the wave model or the particle model of
light? Why?
A. The particle model, because only high-energy frequencies of light
can remove electrons
O B. The wave model, because increasing the brightness causes red
light to remove electrons
C. The wave model, because only high-energy frequencies of light
can bend around a barrier
D. The particle model, because increasing the brightness causes red
light to remove electrons
Answer:
A. The particle model, because only high-energy frequencies of light can remove electrons .
Explanation:
Each photon of blue light has higher energy than each photon of red light has . So when each photon strikes each electron , it gets ejected . But the photon of red light has not sufficient energy to eject electron . Once the photon of red light strikes the electron , the energy is wasted off . Energy of photon can not be accumulated . Thus photon behaves like particle .
Find the electric field E⃗ (r⃗ )E→(r→)E_vec(r_vec) inside the sphere (for rrr< aaa) in terms of the position vector r⃗ r→r_vec. Express your answer in terms of r⃗ r→r_vec, rhorhorho (Greek letter rho), and ϵ0ϵ0epsilon_0.
Solution :
Using the Gauss law, the electric field intensity of a sphere is given by :
[tex]$E. 4 \pi r^2 = \frac{Q_{enc}}{\epsilon_0}$[/tex]
[tex]$E = \frac{Q_{enc}}{4 \pi r^2 \epsilon_0}$[/tex]
Now the enclosed charge inside the sphere (r<a) is
[tex]$Q_{enc}= \rho V$[/tex]
[tex]$Q_{enc}= \rho \left( \frac{4}{3} \pi r^3 \right)$[/tex]
Hence, the electric field intensity becomes as follows :
[tex]$E= \frac{\rho \left(\frac{4}{3} \pi r^3\right)}{4 \pi \epsilon_0 r^2}$[/tex]
[tex]$E =\frac{\rho r}{3 \epsilon_0}$[/tex]
Thus, the electric field inside the sphere is given by :
[tex]$\vec {E} = \frac{\rho \vec{r}}{3 \epsilon_0}$[/tex]
Problem 5. A bullet leaves a rifle with a velocity of 452 m/s. While accelerating through the barrel of the rifle, the bullet moves a distance of 0.93 m. Determine the acceleration of the bullet.
Answer:
1.1 x 10⁵m/s²
Explanation:
Given parameters:
Velocity = 452m/s
distance = 0.93m
Unknown:
Acceleration of the bullet = ?
Solution:
To solve this problem, we use one of the kinematics equation which is given below:
V² = U² + 2aS
V is the final velocity
U is the initial velocity = 0m/s
a is the unknown acceleration
S is the distance traveled
So;
452² = 0² + (2 x a x 0.93)
204304 = 1.86a
a = 1.1 x 10⁵m/s²
guitar produces sound waves when a string is plucked and it vibrates. The measure of the number of the string's vibrations in 1 second is called
A. speed
B. frequency
C. amplitude
D. wavelength
Answer:
i think its B. frequency
Explanation:
please tell me if its wrong but it should be right
What direction does energy transfer to the direction of a light wave
Answer:
light is a transverse wave. The direction of energy transfer is perpendicular to the motion of the wave
Explanation:
Light is an example of a wave that transfers energy through empty space. How are all mechanical waves similar? The waves caused by an earthquake are good examples of energy transfer. The disturbed ground shakes from side to side and up and down as the waves move through it,
Why we need football?
Answer:
bc we play when we are bored and some people use it as a tradition to play on thanksgiving
what energy happens when you plug in a blender?
Answer:
Electrical to kinetic
Explanation:
Answer:
Electrical energy is supplied to the blender.
Explanation:
This is converted into kinetic energy to turn the blades that blend the food, so energy is transferred from electrical to kinetic.
This is the useful energy change that we most want to happen.
You're welcome, have a good day :)
What is the net force in this picture?
hellllllllllllllllllloppppppppppppppppppp mmmmmmmmmmmmeeeeeee
Answer:
I'M SORRY I CAN'T SEE THE PICTURE BUT IT WILL MOST LIKELY BE THE DIFFERENCE BETWEEN THE NUMBERS
Explanation:
for instance if there was someone pushing a desk with a net force of 9 towards the right, the net force would come to a total of 9 since there is no one on the other side pushing the desk. Meaning the desk would go right. I'm sorry if this isn't what you needed D:
0.0135 kg of steam at 100°C is
cooled, which turns it into water at
50.0°C. How much heat has been
removed? (Remember, it has to
change phase before cooling
down.)
Boil Pt (°C)
Material Melt Pt (°C) 4 0/kg)
Water
0
3.33.105
L(/kg) c (J/(kg*C))
2.26.106 4186
100
(Unit = J)
Answer:
33333.35 kg
Explanation:
I got it right on Acellus, rounded to 33300 sigfigs
When 0.0135 kg of steam at 100°C is cooled, turns it into water at 50.0°C. Then 33,342.45 J of heat has been removed.
What is latent heat?Latent heat is the heat absorbed or released by a substance during a change in its physical state without a corresponding change in temperature. This means that the heat energy is being used to break or form intermolecular bonds between the particles in the substance, rather than raising or lowering the temperature. Examples of processes that involve latent heat include melting, freezing, vaporization, and condensation. The amount of heat required or released during these phase transitions is dependent on the substance and the amount of material undergoing the change.
Here in the question,
To solve this problem, we need to use the formula for the heat required to change the phase of a substance, which is given by:
Q = m * L
where Q is the heat required, m is the mass of the substance, and L is the specific latent heat of the substance.
In this case, we need to find the heat required to change 0.0135 kg of steam at 100°C to water at 100°C, and then cool it down to 50°C.
First, we need to find the heat required to change the phase of the steam to water at 100°C. Using the table given, we can see that the specific latent heat of vaporization for water is 2.26 × 10^6 J/kg. So the heat required to change 0.0135 kg of steam to water at 100°C is:
Q1 = m * L = 0.0135 kg * 2.26 × 10^6 J/kg = 30,510 J
Next, we need to find the heat required to cool the water from 100°C to 50°C. Using the specific heat capacity of water, which is 4186 J/(kg°C), we can calculate the heat required as:
Q2 = m * c * ΔT = 0.0135 kg * 4186 J/(kg°C) * (100°C - 50°C) = 2832.45 J
The total heat removed is the sum of the heat required to change the phase of the steam and the heat required to cool the water:
Q = Q1 + Q2 = 30,510 J + 2832.45 J = 33,342.45 J =33.34245 kJ.
Therefore, 33,342.45 J of heat has been removed.
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3.5 kg object experience an acceleration of o.5 m/s^. What net force does the object experience?
A. 1.5 N
B. 1.75 N
C. 3.5 N
D. 7 N
Answer:A heavy box has a mass of 30 kg. The box experiences a net force of 90 N when pushed along the floor. Use
this information to answer questions 17 and 18
Explanation:
17. What is the acceleration of the box?
a. 3 m/s 2 b. 2 m/s 2 c. 0.3 m/s 2 d. 0.5 m/s 2
18. If the mass of the box was changed to one third as much, and the force was held constant, how would
the acceleration change?
a. It would be one third as much
b. It would be 3 times as much
c. It would be one half as much
d. It would be 2 times as much
Use the Electrostatic Series to predict the charges on the following pairs of substances when they are rubbed together:
A glass coffee table and a cotton dusting cloth
A rubber balloon and human hair
A plastic comb and cat fur
An ebonite rod and a piece of silk
A crate is dragged up a ramp at constant speed. The work done on the system can be accounted for by:
- Eel
-Eg
-Ek
-Eint
-both Eg and Eint
Answer:
The work done on the system can be accounted for by;
Both [tex]E_g[/tex] and [tex]E_{int}[/tex]
Explanation:
The speed of the crate = Constant
Therefore, the acceleration of the crate = 0 m/s²
The net force applied to the crate, [tex]F_{NET}[/tex] = 0
Therefore, the force of with which the crate is pulled = The force resisting the upward motion of the crate
However, we have;
The force resisting the upward motion of the crate = The weight of the crate + The frictional resistance of the ramp due to the surface contact between the ramp and the crate
The work done on the system = The energy to balance the resisting force = The weight of the crate × The height the crate is raised + The heat generated as internal energy to the system
The weight of the crate × The height the crate is raised = Gravitational Potential Energy = [tex]E_g[/tex]
The heat generated as internal energy to the system = [tex]E_{int}[/tex]
Therefore;
The work done on the system = [tex]E_g[/tex] + [tex]E_{int}[/tex].
Newton’s 2nd Law: F=ma. If you push a shopping cart with 130 N of force, and it accelerates at 3 m/s², what is the mass of the cart?
Answer:
43.3kg
Explanation:
Given parameters:
Force = 130N
Acceleration = 3m/s²
Unknown:
Mass of cart = ?
Solution:
From Newton's second law of motion:
F = m x a
F is the force on the body
m is the mass
a is the acceleration
So;
m = [tex]\frac{F}{a}[/tex] = [tex]\frac{130}{3}[/tex] = 43.3kg
What do electric and magnetic fields have in common?
Electric field, an electric property associated with each point in space when charge is present in any form. The magnitude and direction of the electric field are expressed by the value of E, called electric field strength or electric field intensity or simply the electric field.
Magnetic field are a region around a magnetic material or a moving electric charge within which the force of magnetism acts. Magnetic fields are produced by moving electric charges. Everything is made up of atoms, and each atom has a nucleus made of neutrons and protons with electrons that orbit around the nucleus. Since the orbiting electrons are tiny moving charges, a small magnetic field is created around each atom.
Similarities between magnetic fields and electric fields: Magnetic fields are associated with two magnetic poles, north and south, although they are also produced by charges (but moving charges). Like pole repel unlike poles attract. Electric field points in the direction of the force experienced by a positive charge.
If the density of a diamond is 3.5 /cm^ 3 what would be the mass of a diamond whose volume is 0.5 cm ^ 3 ?
Answer:
1.75g
Explanation:
Given parameters:
Density = 3.5g/cm³
Volume = 0.5cm³
Unknown:
Mass of the diamond = ?
Solution:
Density is the mass per unit volume of a substance
Density = [tex]\frac{mass}{volume}[/tex]
So;
Mass = 3.5 x 0.5 = 1.75g
A baseball player hits a baseball with a bat. The mass of the ball is 0.25 kg. The ball accelerates at 200 m/s2
What is the force, to the nearest N, of the bat on the baseball?
Answer:
50N
Explanation:
Force (N) = mass (kg) × acceleration (m/s²)
0.25kg times 200m/s² = 50N
The force, to the nearest N, of the bat on the baseball is 50 Newtons.
Given the data in the question;
Mass of ball; [tex]m = 0.25kg[/tex]Acceleration; [tex]a = 200m/s^2[/tex]Force; [tex]F = \ ?[/tex]
To determine the force, we use Newton's second law of motion:
[tex]F = m * a[/tex]
Where m is mass and a is acceleration
We substitute our values into the equation;
[tex]F = 0.25kg * 200m/s^2\\\\F = 50 kg.m/s^2\\\\F = 50N[/tex]
Therefore, the force, to the nearest N, of the bat on the baseball is 50 Newtons.
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A suitcase with a mass of kg 2 has a weight of 18n on a particular planet. What is the acceleration due to gravity on that planet
Answer:
[tex]9\ \text{m/s}^2[/tex]
Explanation:
m = Mass of the object = 2 kg
W = Weight of the object = 18 N
g = Acceleration due to gravity
Weight of the an object is given by
[tex]W=mg[/tex]
[tex]\Rightarrow g=\dfrac{W}{m}[/tex]
[tex]\Rightarrow g=\dfrac{18}{2}[/tex]
[tex]\Rightarrow g=9\ \text{m/s}^2[/tex]
The acceleration due to gravity on that planet is [tex]9\ \text{m/s}^2[/tex].
how can Magnets cause objects to have kinetic energy?
SOMEONE PLZ HELP!!!! Lots of points
Answer:
If there is a system of magnets being held in place, there is potential energy. When you let go, the potential energy converts to kinetic energy and the magnets move. Putting the system of magnets close together which creates an opposing force.
Explanation:
Magnets cause objects to have kinetic energy by the magnetic force present in the magnet.
Magnets is a material which has a strong magnetic field which attracts ferromagnetic substances such as nickle, iron etc.
When a ferromagnetic objects put near the magnet, the magnet attracts the object and causes the movement towards its direction.
Therefore, magnets cause objects to have kinetic energy by the magnetic force present in the magnet.
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What is a light year?
A: the distance light travels in one earth year
B: the time it takes light to travel across the universe
C: the distance light travels in one orbit of the moon
D: the distance light travels from the sun to the earth
Answer:
A: The distance light travels in one year
plzz helpp mee!!!! plzzz
A Student missed the bus and had to walk 2 miles West to school. They got detention and missed the bus back, so they had to walk 2 miles East to get home. What is the total Distance the student traveled?
If you add 2 miles from west then 2 miles east then it would 4 miles all together.
What is Required for the energy of an object to change
Which is a unit of momentum?
A) N-m/s
B) kg-m/s
C) kg-m/s2
D) N-m/s2
please hurry i need help asap, will mark brainliest
Answer:
unit of momentum is kgm/s2
The unit for momentum can be Newton-second (Ns). In the CGS system, if the mass is in grams and the velocity in centimeters per second, then the unit of momentum will be gram-centimeters per second (g⋅cm/s).
What is momentum ?"Momentum, product of the mass of a particle and its velocity. Momentum is a vector quantity; i.e., it has both magnitude and direction. Isaac Newton's second law of motion states that the time rate of change of momentum is equal to the force acting on the particle. See Newton's laws of motion."
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Who ever helps can you help me with some other ones?
Answer:
2 seconds
Explanation:
It only went up by 2
Based on the figure shown, about how far can sound travel in water in 2.5 s if the water temperature is 25°?
O a. 3,750 m
Oc. 600 m
Ob. 375 m
O d. 875 m
Answer:
A
Explanation:
Working to ensure that women get paid the same as a man for the same work is an example of? Social dysfunction, soical conflict, social justice, or social engineering?
Answer:
social justice is the correct answer
Explanation:
Question 1(Multiple Choice Worth 2 points)
(04.06 LC)
Hydrogen is in column 1 of the periodic table. What information does this give us?
There is one other element that hydrogen will bond with.
There is one neutron in the nucleus.
The mass of the atom is one.
There is one electron in the outer energy level.
Answer:
D
Explanation:
the reason for each column is to show the electronic configuration of the elements in that column.
Hope This Helps ▼・ᴥ・▼
What does a velocity measurement include that a speed measurement does not? A: Time B:direction C:distance D: acceleration
Answer:
B. Direction
Explanation:
Speed is a scalar quantity and doesn't keep track of direction : Velocity is a vector quantity and is direction aware.
The acceleration due to gravity is 9.81 m/s2, towards the Earth. Rain falling from an altitude of 9,000 m would fall for about 1.5 minutes before hitting the ground (ignoring air resistance). What would be the final speed of a raindrop by the time it reaches the ground?
Answer:
the final speed of the rain is 541 m/s.
Explanation:
Given;
acceleration due to gravity, g = 9.81 m/s²
height of fall of the rain, h = 9,000 m
time of the rain fall, t = 1.5 minutes = 90 s
Determine the initial velocity of the rain, as follows;
[tex]h = ut + \frac{1}{2} gt^2\\\\9000 = 90u + \frac{1}{2} (9.8)(90)^2\\\\9000 = 90u + 39690\\\\90u = -30690\\\\u = \frac{-30690}{90} \\\\u = -341 \ m/s[/tex]
The final speed of the rain is calculated as;
[tex]v^2 = u^2 + 2gh\\\\v^2 = (-341)^2 + 2(9.8\times 9000)\\\\v^2 = 292681\\\\v = \sqrt{292681} \\\\v = 541 \ m/s[/tex]
Therefore, the final speed of the rain is 541 m/s.
Answer:
The magnitude of the final speed of a raindrop by the time it reaches the ground will be 541.45 m/s.
Explanation:
The final speed of the raindrop can be found using the following equation:
[tex] v_{f} = v_{0} - gt [/tex]
Where:
[tex]v_{f}[/tex]: is the final speed =?
[tex]v_{0}[/tex]: is the initial speed
g: is the acceleration due to gravity = 9.81 m/s²
t: is the time = 1.5 min
First, we need to find the initial speed:
[tex] y_{f} = y_{0} + v_{0}t - \frac{1}{2}gt^{2} [/tex]
Where:
[tex]y_{f}[/tex]: is the final height = 0
[tex]y_{0}[/tex]: is the initial height = 9000 m
Hence, the initial speed is:
[tex] v_{0} = \frac{y_{f} - y_{0} + \frac{1}{2}gt^{2}}{t} = \frac{0 - 9000 m + \frac{1}{2}9.81 m/s^{2}*(90 s)^{2}}{90 s} = 341.45 m/s [/tex]
Hence, the final speed is:
[tex] v_{f} = v_{0} - gt = 341.45 m/s - 9.81 m/s^{2}*90 s = -541.45 m/s [/tex]
Therefore, the magnitude of the final speed of a raindrop by the time it reaches the ground will be 541.45 m/s.
I hope it helps you!
Food labels often indicate energy in joules and calories. A jar of jam contains 1030 kJ (245 kcal).
Check if that is correct.
Answer:
It is not correct.
The correct conversion is:
1030 KJ = 246.18 KCal.
Explanation:
To know if 1030 KJ is equivalent to 245 KCal, we shall convert 1030 kJ to kcal. This can be obtained as follow:
4.184 KJ = 1 KCal
Therefore,
1030 KJ = 1030 KJ × 1 KCal / 4.184 KJ
1030 KJ = 246.18 KCal.
Thus, 1030 KJ is equivalent to 246.18 KCal.
From the above calculation, we can see that:
1030 KJ ≠ 245 KCal
Rather,
1030 KJ = 246.18 KCal.
A rescue pilot drops a survival kit while her plane is flying at an ultitude of 2500m with a forward velocity of 95m. If the air friction is disregarded, how far advance of the starving explorer’s drop zone should she release the package?
Answer:
Approximately [tex]2.1\; \rm km[/tex], assuming that [tex]g = -9.8\; \rm m \cdot s^{-2}[/tex].
Explanation:
Let [tex]t[/tex] denote the time required for the package to reach the ground. Let [tex]h(\text{initial})[/tex] and [tex]h(\text{final})[/tex] denote the initial and final height of this package.
[tex]\displaystyle h(\text{final}) = \frac{1}{2}\, g\, t^2 + h(\text{initial})[/tex].
For this package:
Initial height: [tex]h(\text{initial}) = 2500\; \rm m[/tex].Final height: [tex]h(\text{final}) = 0\; \rm m[/tex] (the package would be on the ground.)Solve for [tex]t[/tex], the time required for the package to reach the ground after being released.
[tex]\displaystyle t^{2} = \frac{2\, (h(\text{final}) - h(\text{initial}))}{g}[/tex].
[tex]\begin{aligned} t &= \sqrt{\frac{2\, (h(\text{final}) - h(\text{initial}))}{g} \\ &\approx \sqrt{\frac{2\times (0\; \rm m - 2500\; \rm m)}{(-9.8\; \rm m \cdot s^{-2})}} \approx 22.588\; \rm s\end{aligned}[/tex].
Assume that the air resistance on this package is negligible. The horizontal ("forward") velocity of this package would be constant (supposedly at [tex]95\; \rm m \cdot s^{-1}[/tex].) From calculations above, the package would travel forward at that speed for about [tex]22.588\; \rm s[/tex]. That corresponds to approximately:[tex]95\; \rm m \cdot s^{-1} \times 22.588\; \rm s \approx 2.1 \times 10^{3}\; \rm m = 2.1\; \rm km[/tex].
Hence, the package would land approximately [tex]2.1\; \rm km[/tex] in front of where the plane released the package.