Answer:
Positive
Explanation:
In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive
An 8.0g bullet, moving at 400 m/s, goes through a stationary block of wood in 4.0 x 10^-4s, emerging at a speed of 100 m/s. (a) what average force did the wood exert on the bullet? (b) how thick is the wood?
Answer:
Explanation:
Initial velocity (u) of the Bullet = 400 m/sec
Final velocity (v) of the Bullet = 100 m/sec
Bullet passed through the block in (t) = 0.0004 sec
Using 1st Equation of motion :
400 m/s = 100 m/s - a (0.0004)
Deceleration of Bullet = 750,000 m/sec^2
(a) F (force exerted by the wooden block on the bullet) = F (force exerted by the bullet on the wooden block)
F = m * a = 0.008 * 750,000 = 6000 N
(b) Using 3rd Equation of motion :
[tex]v^{2} = u^{2} - 2aS[/tex]
10000 = 160000 - 2 * 750,000 * S
Thickness of wood (S) = 0.1 m
fill in the blanks
1.)Seed drill is used for ____ of the seeds.
2.)ploughing helps the_____of roots of the growing plants.
3.)Tilling of the soil is also called a ________.
4.)Manure and fertilizers are use ti maintain the______of the soil.
5.)A most common weedicide is________.
6.)After harvesting,grains are separated from the chaffand hay by _______ or by using ______.
7.)The economial methods of irrigation are_____and____.
8.)The wild plants which grow along with the main crop are called_________.
9.) Shifting of tiny plants from a nursery to the main field is called______.
10.) Excess water and wet soil do not permit proper_____of the seeds or roots of the plants.
Answer:
1.) Sowing
2.) Respiration
3.) Soil preparation or cultivation or ploughing
4.) Fertility
5.) 2, 4 -D
6.) winnowing threshers
7.) Surface irrigation and sprinkler irrigation
8.) Weeds
9.) Transplantation
10.) Aeration
Explanation:
1.) Seed drill sows crop seed
2.) Ploughing assist in the respiration and penetration of the roots of a growing plants
3.) Tilling the soil is breaking of the soil lumps and turning of the soil
4.) Manure and fertilizers supply nutrient to the soil for the uptake by plant in food production
5.) 2, 4 -D are a range of weedicide containing 2,4-D as the active ingredient
6.) Winnowing is the separation of grain from straw
Threshers remove seeds from husks and stalks
7.) Surface irrigation -gravity enables the flow of the water
and sprinkler irrigation- Use of preset tools for irrigation
8.) Weeds are the unwanted, in situ, growing plants close to the crops
9.) Transplantation is the method of relocating plants
10.) Excess water limits access of the roots and seeds to atmospheric oxygen
Una partícula se mueve en el plano XY efectúa un desplazamiento mientras actúa sobre ella una fuerza constante. X= (4i + 3j) m, F = (16i + 12j) N a) Calcule la magnitud del desplazamiento y la de la fuerza. B) Calcule el trabajo realizado por la fuerza F c) Calcule el ángulo entre F y x.
Answer:
a) La magnitud del desplazamiento es de 5 m
La magnitud de la fuerza es 20 N
b) El trabajo realizado por la fuerza es de 100 J
c) El ángulo entre la fuerza y el plano es 0 °
Explanation:
a) La magnitud del desplazamiento se encuentra por la relación;
[tex]\left | X \right | = \sqrt{X_{x}^{2}+X_{y}^{2}}[/tex]
Lo que da;
[tex]\left | X \right | = \sqrt{4^{2}+3^{2}} = 5 \ m[/tex]
De manera similar, la magnitud de la fuerza, F, se encuentra como sigue;
[tex]\left | F \right | = \sqrt{F_{x}^{2}+F_{y}^{2}}[/tex]
Lo que da;
[tex]\left | F \right | = \sqrt{16^{2}+12^{2}} = 20 \ N[/tex]
b) El trabajo, W, realizado por la fuerza = Fuerza, F × Distancia, X
∴ Ancho = 20 N × 5 m = 100 N · m = 100 J
c) La dirección de la fuerza viene dada por la siguiente fórmula;
[tex]tan^{-1} \left (\dfrac{F_y}{F_x} \right ) = tan^{-1} \left (\dfrac{12}{16} \right ) = 38.9^{\circ}[/tex]
La dirección del plano viene dada por la siguiente fórmula;
[tex]tan^{-1} \left (\dfrac{X_y}{X_x} \right ) = tan^{-1} \left (\dfrac{3}{4} \right ) = 38.9^{\circ}[/tex]
Por tanto, el ángulo entre la fuerza y el plano = 0 °
La fuerza actúa a lo largo del plano.
Can someone please illustrate how the refracted ray will look like?
Answer
As the angle of incidence increases in Figure 2.8, a point is finally reached where the refracted ray does not emerge at the second layer but lie along the interface. This particular angle of incidence at which the angle of refraction is 90° and the refracted ray lies along the interface is known as the critical angle. At and beyond the critical angle, there is no transmitted ray and therefore a very high reflected ray will be recorded .
Therefore,
sinθisin90=Vp1Vp2
But, sin 90 = 1.
At critical angle,
sinθcritical=Vp1Vp2
A critical refracted wave travels along the interface between layers and is refracted back into the upper layer at the critical angle. The waves refracted back into the upper layer are called head waves or first-break refractions because at certain distances from a source, they are the first arriving energy. Recorded first-break refraction is shown in Figure 2.10.
Note that these first-break refractions can give us important information about the shallow velocities on land seismic data.
Note also that seismic data are acquired in such a way that reflections from horizons of interest are in the pre-critical region, even at the farthest offset in the data.
In reality, part of the seismic energy arriving at an interface is transmitted and refracted, and another part of the energy is reflected at that same interface. Given that there are many reflectors in the subsurface, there will be many paths from source to receiver, each of them with a different travel time. The proportion of energy reflected depends on the material properties of the two bounding layers and on the angle of incidence
element x has two isotopes: x-27 and x-29. x-27 has an atomic mass of 26.975 and a relative abundance of 82.33%, and x-29 has an atomic mass of 29.018 and a relative abundance of 17.67%. calculate the atomic mass od element x. show your work
Answer:
27.336
Explanation:
The atomic mass is the weighted average of the atomic masses of the isotopes. Simply multiply each isotopes's atomic mass by its relative abundance, then sum the results.
m = 0.8233 × 26.975 + 0.1767 × 29.018
m = 27.336
Light travels at a speed of 2.998*108 m/s. Light takes approximately 3.25 minutes to travel from the Sun to reach a planet. Calculate the distance from the Sun to this planet in meters. Give your answer to 0 decimal places.
Answer:
585×10⁸ m
Explanation:
Distance = rate × time
d = (2.998×10⁸ m/s) (3.25 min) (60 s/min)
d = 585×10⁸ m
how do you find average velocity
Answer:
find the sum of the inital and final velocitys and divide by 2 to find the average
You and your family are going on a trip in Europe. Calculate the speed in the following scenario. State how you calculated your answer and include correct units. A car travels 240 kilometers in 3 hours; What is the speed of the car during that time?
Answer:
22.2 m/s or 80 km/h
Explanation:
Given that
Distance travelled by the car, d = 240 km
Time taken by the car, t = 3 hours.
Speed of the car, v = ? m/s
for easy calculations, we will be converting the units to meters and seconds respectively.
240 km to meters would be
240 * 1000 m = 240000 m
3 hrs to seconds would be
3 * 60 mins * 60 seconds = 10800 s
now, we have our distance and time to be
d = 240000 m
t = 10800 s
speed is defined as the ratio of distance with respect to time taken, effectively,
Speed = distance/time
speed, v= 240000 / 10800
v = 22.2 m/s
therefore, the speed of the car during the time is 22.2 m/s, or if the speed is needed in km/h, we can convert it
22.2 * 3600/1000 =
80 km/h
Will mark as BRAINLIEST.......
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation 4x³+3x²-5x+2 , where x is in meters and t is in sec.
a)Find velocity of particle at i) t=2 sec ii) t=4 sec.
b) Find the acceleration of the particle at t=3 sec.
Explanation:
It is given that,
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation as:
[tex]x=4t^3+3t^2-5t+2[/tex]
Where,
x is in meters and t is in sec
We know that,
Velocity,
[tex]v=\dfrac{dx}{dt}\\\\v=\dfrac{d(4t^3+3t^2-5t+2)}{dt}\\\\v=12t^2+6t-5[/tex]
(a) i. t = 2 s
[tex]v=12(2)^2+6(2)-5=55\ m/s[/tex]
At t = 4 s
[tex]v=12(4)^2+6(4)-5=211\ m/s[/tex]
(b) Acceleration,
[tex]a=\dfrac{dv}{dt}\\\\a=\dfrac{d(12t^2+6t-5)}{dt}\\\\a=24t+6[/tex]
Pu t = 3 s in above equation
So,
[tex]a=24(3)+6\\\\a=78\ m/s^2[/tex]
Hence, (a) (i) v = 55 m/s (ii) v = 211 m/s and (b) 78 m/s²
Distinguish between concave mirror and convex mirror
Answer:
Concave mirror makes someone looking at it look dwarf or short, while convex mirror stretches the person making the person look weird.
Which waves move fast Longitudinal waves or Transverse waves and why???
Answer:
Transverse wave
Explanation:
Its because in transverse wave the particle displacement is perpendicular to the direction of wave propagation..hope it helps you...
If the mass of a ball is 50g on a height of 8m. Calculate the kinetic energy when it has a velocity of 3m/s.
Answer:
kinetic energy is 1/2mv^2.
which is 1/2×0.05×3^2
1/2×0.05×9.
1/2×0.45=
0.45÷2=0.225~0.23J
6. Match the statements given in column 'A' with those in column 'B':
alse, (un) False, (ve
Column A
1. Urea
2. Combines
3. Silos
4. Seed drills
5. Irrigation
6. Tilling
Column 'B'
(a) Sowing of seeds
(b) Storage of grains
(c) Harvesting and threshing
(d) Fertilizer
(e) Preparation of soil
(f)Sprinklers
Answer:
1. Urea, (d)Fertilizer
2. Combines, (c) Harvesting and threshing
3. Silos, (b) Storage of grains
4. Seed drills, (a) Sowing seeds
5. Irrigation, (f) Sprinklers
6. Tilling, (e) Preparation of soil
Explanation:
1) Urea is a widely used and important fertilizer in the agricultural industry
2) The combine harvester combines three categories of harvesting grain drops such as threshing reaping and winnowing
3) Silos are used to store grains
4) A seed drill is a seed planting mechanism for burying seeds to a particular depth during seed planting
5) Irrigation is the application of required volume of water to plants
6) Tilling is the digging, turning, and staring operations meant to prepare the soil.
A foot is 12 inches and a mile is 5280 ft, exactly. A centimeter is exactly 0.01m or mm. Sammy is 5 feet and 5.3 inches tall. What is Sammy's Height in inches?
The answer is 65.3 inches tall
Explanation:
To know the heigh of Sammy in inches it is necessary to convert the 5 feet to inches and add this number to 5.3 inches as the statement mentions "Sammy is 5 feet and 5.3 inches tall". Additionally, it is known each foot is equal to 12 inches ( 1 foot = 12 inches). According to this, the simplest method to convert feet to inches is to multiply the feet given by 12. The process is shown below:
1 foot = 12 inches
feet to inches = number of feet x 12
5 feet x 12 = 60 inches
This means 5 feet is equal to 60 inches. Now, 60 inches + 5.3 inches = 65.3 inches (total height of Sammy in inches)
A 5000 g toy car starts from rest and moves a distance of 300 cm in 3 s under the action of a single constant force. Determine the magnitude of the force? help good answer please
Answer:
3.33 N
Explanation:
First, find the acceleration.
Given:
Δx = 3 m
v₀ = 0 m/s
t = 3 s
Find: a
Δx = v₀ t + ½ at²
3 m = (0 m/s) (3 s) + ½ a (3 s)²
a = ⅔ m/s²
Use Newton's second law to find the force.
F = ma
F = (5 kg) (⅔ m/s²)
F ≈ 3.33 N
what energy is used when we drink a sip of juice?
Answer:
mechanical energy or chemical energy
If the spring constant is 10 N/m and the spring is stretched 1 m, what is the Force?
Answer:
10N
Explanation:
Applying the Hooke law:
F = kx
F: Force
k: stiffness coefficient
x: stretched distance
F = 10N/m x 1m = 10N
In no more than five simple statements, use the kinetic theory to explain why an iron bar expands when it is heated.
Answer:
Iron expands because heating increases the space between the molecules
Explanation:
According to the kinetic molecular theory, all matter is composed of atoms and molecules which are in constant motion.
When a substance is heated, molecules of the substance begin to vibrate faster. This faster vibration leads to increased space between the molecules (expansion) . The kind of motion motion and degree of spacing of the molecules determine the state of matter in which the substance is found.
Hence, when an iron bar is heated, it expands due to increased motion of its molecules leading to spaces between them.
Tita= 55°
Answer and proper explanation pls in English
Answer:
the photo is a bit blur
The period of a pendulum is the time it takes the pendulum to swing back and forth once. If the only dimensional quantities that the period depends on are the acceleration of gravity, g, and the length of the pendulum, ℓ, what combination of g and ℓ must the period be proportional to? (Acceleration has SI units of m • s-2.)
Answer: √(L/g)
Explanation:
Here we only work with the units:
The unit of the period is units of time, so we have:
[T] = [s]
Now, the units of the length of the pendulum are units of distance:
[L] = [m]
And the units of the acceleration are:
[g] = [m/s^2]
Now, we want to work with those two in such way that the end result is only in seconds.
First, we can see that in g we have seconds square, so we know that we should use a square root.
Then we can divide L by g in order to remove the distance unit, and to have the time unit in the numerator
[L/g] = [m*s^2/m] = [s^2]
Now we apply the square root:
[√(L/g)] = [√s^2] = [s]
Then the combination is: √(L/g)
T = k*√(L/g)
where k is the constant of proportionality.
Determine the magnitude of the force that must be applied to a wooden block whose weight has a magnitude of 8N, so that it acquires an acceleration of 0.5 m / s²
Answer:
0.4 N
Explanation:
The weight mg is 8 N, so the mass is:
mg = 8 N
m = 8 N / g
m = 8 N / (10 m/s²)
m = 0.8 kg
The force needed to accelerate it to 0.5 m/s².
F = ma
F = (0.8 kg) (0.5 m/s²)
F = 0.4 N
Monochromatic light shines on the cathode in a photoelectric effect experiment, causing the emission of electrons. If the frequency of the light stays the same but the intensity of the light shining on the cathode is increased:_________
a. The emitted electrons will be moving at a higher speed.
b. There will be more electrons emitted.
c. Neither A nor B are true.
d. Both A and B are true
Answer:
b. There will be more electrons emitted.
Explanation:
In photoelectric emission, the energy of the emitted electron is dependent on the frequency of the wave incident on the plate; but not the intensity. The rate of electron emission per unit time however depends on the intensity of the incident light. So increasing the intensity of the light at constant frequency will only affect the number of electrons emitted per unit time.
Express the time spent to daily life activities during holidays as a fraction of whole day 1. Represent the fractions in pictorial form. 2. Write the fractions in simplest form. 3. Arrange them in ascending order.
Answer:
(II). The fractions in simplest form
[tex]\dfrac{31}{35}[/tex], [tex]\dfrac{91}{165}[/tex] and [tex]\dfrac{13}{5}[/tex]
(III). The fractions in ascending order
[tex]\dfrac{91}{165}<\dfrac{31}{35}<\dfrac{13}{5}[/tex]
Explanation:
Given that,
(I). Represent the fractions in pictorial form
(II). Write the fractions in simplest form.
(III). Arrange them in ascending order.
Suppose, The fractions in pictorial form
(a). [tex]\dfrac{3}{5}+\dfrac{2}{7}[/tex]
(b). [tex]\dfrac{9}{11}-\dfrac{4}{15}[/tex]
(c). [tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}[/tex]
We need to write in simplest form
Using given fraction
(a). [tex]\dfrac{3}{5}+\dfrac{2}{7}=\dfrac{3\times7}{5\times7}+\dfrac{2\times5}{7\times5}[/tex]
[tex]\dfrac{3}{5}+\dfrac{2}{7}=\dfrac{21}{35}+\dfrac{10}{35}[/tex]
[tex]\dfrac{3}{5}+\dfrac{2}{7}=\dfrac{21+10}{35}[/tex]
[tex]\dfrac{3}{5}+\dfrac{2}{7}=\dfrac{31}{35}[/tex]
(b). [tex]\dfrac{9}{11}-\dfrac{4}{15}=\dfrac{9\times15}{11\times15}-\dfrac{4\times11}{15\times11}[/tex]
[tex]\dfrac{9}{11}-\dfrac{4}{15}=\dfrac{135-44}{165}[/tex]
[tex]\dfrac{9}{11}-\dfrac{4}{15}=\dfrac{91}{165}[/tex]
(c). [tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}=\dfrac{7}{10}+\dfrac{2\times2}{5\times2}+\dfrac{3\times5}{5\times2}[/tex]
[tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}=\dfrac{7}{10}+\dfrac{4+15}{10}[/tex]
[tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}=\dfrac{7+4+15}{10}[/tex]
[tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}=\dfrac{26}{10}[/tex]
[tex]\dfrac{7}{10}+\dfrac{2}{5}+\dfrac{3}{2}=\dfrac{13}{5}[/tex]
We need to arrange them in ascending order
Using simplest form
The simplest fraction in ascending order
[tex]\dfrac{91}{165}<\dfrac{31}{35}<\dfrac{13}{5}[/tex]
Hence, This is required solution.
Which is the second step of the fusion process?
O
H+1H - ?H+e+ + v + energy
O 6(3H) +21_e) - He +24H) + energy + 2u
{H+1H He + energy
O
He He He + 1H+1H + energy
Answer:
The correct option is;
[tex]_{1}^{2}\textrm{He} + _{1}^{1}\textrm{H} \rightarrow _{3}^{2}\textrm{He} + energy[/tex]
Explanation:
The second step of the fusion process is the reaction (combination) where a Deuterium combines with a hydrogen to produce one helium 3, 3He, nucleus and a energy photon as follows;
[tex]_{1}^{2}\textrm{He} + _{1}^{1}\textrm{H} \rightarrow _{3}^{2}\textrm{He} +\gamma \ (energy)[/tex]
After which the produced Helium-3 combines to form the Helium nucleus an emit 2 protons
Steps 1 and 2 are take place two times (producing 26 MeV energy) before the step three (the combination of the formed helium-3) takes occurs.
Answer:
C on edge
Explanation:
Just did it and got it right :)
A magnet pulls a piece of iron with a force of 1 N. What is the force that the iron piece exerts on the magnet?
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the same direction.
The iron piece exerts a force of 1 N on the magnet in the opposite direction.
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the opposite direction.
The iron piece exerts a force of 1 N on the magnet in the same direction.
Answer:
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
Explanation:
In this exercise they give us the force exerted by a magnet on an iron bar and ask us the force that the iron bar exerts on the magnet. We can see that these are action and reaction forces, which by Newton's third law must be of equal magnitude and opposite direction, each applied to one of the bodies.
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
Which of the following best describes a consumer?
0. a business owner who sells clothes
0. someone who studies economics
O. a farmer who sells his crops
O. a person who buys goods and services
Answer:
a business who buys goods and services
What is necessary for a ball to be in translational equilibrium?
Answer:
In order to be in translational equilibrium, the net force (sum of the forces) must be 0.
Self-Check
por Learning
A truck mass 8000 kg and a car a mass 1000
kg are travelling at the same velocity. Which one has greater kinetic energy ? Why?
Answer:
K.E of truck > K.E of car
Explanation:
Mass of the truck = 8000Kg
K.E=[tex]\frac{1}{2} mv[/tex]
K.E =[tex]\frac{1}{2}*8000*v\\ 4000v[/tex]
Mass of the car = 1000 Kg
K.E of the car =[tex]\frac{1}{2}*1000*v\\ 500v[/tex]
Therefore Kinetic energy of the truck is greater than that of the car
wholesale market definition
Answer:
Wholesale Market. 1. The market for the sale of goods to a retailer. That is, a wholesaler receives large quantities of goods from a manufacturer and distributes them to stores, where they are sold to consumers. ... The market for the sale of securities to institutional investors rather than individuals.
A laser beam is incident on two slits with a separation of 0.210 mm, and a screen is placed 5.05 m from the slits. If the bright interference fringes on the screen are separated by 1.59 cm, what is the wavelength of the laser light?
Answer:
0.66*10^-6m
Explanation:
We know that the bright fringes are placed on the screen as follows
Ym= m*(lambda xL/d)
But we are given
L= 5.05
Deta Y= 1.59
d = 0.21
1.59* 10^-2m= lambda * 5.05m/2.1*10^-4m
So lambda=
1.59* 10^-2m x 2.1*10^-4m/ 5.05m
= 0.66*10^-6m
