Answer:
S1 = 1/2 g t^2 distance stone falls in time t
S2 = Vy t - 1/2 g t^2 distance thrown stone rises in time t
H = 49 = S1 + S2 = Vy t
t = 49 / 40 sec time when stones meet
Check:
Stone 1 falls: 1/2 g t^2 = 1/2 * 9.8 * (49 / 40)^2 = 7.35 m
Stone 2 rises : 40 * (49 / 40) - 1/2 * 9.8 (49 / 40)^2 = 41.65 m
To pull a box up a rough slope,the force required will be least when it is applied :
a) horizontaly
b) vertically
c) perpendicular to the plane
d) parallel to the plane
Answer:
The correct option is;
d) Parallel to the plane
Explanation:
The forces acting on the box of mass, m are;
Weight of the box acting an angle, θ, equal to the inclination of the plane to the perpendicular of the plane
Weight of the box acting along the plane = m×g×sin(θ)
The force of friction along the plane = μ×m×g×cos(θ)
The total force acting downward along the plane [tex]F_{down}[/tex], = m×g×sin(θ) + μ×m×g×cos(θ)
The Force needed to pull the box up along the plane F = The total force acting downward along the plane
F = m×g×sin(θ) + μ×m×g×cos(θ) = m×g×(sin(θ) + μ×cos(θ))
When the force, Fₐ is applied vertically, the force acting along the plane = Fₐ×cos(θ)
When the force is applied perpendicular, the force acting along the plane = Fₐ×sin(θ)
When the force is applied horizontally, the force acting along the plane = Fₐ×cos(θ)
When the force is applied parallel to the plane, the force acting along the plane = Fₐ
Therefore, since Fₐ > Fₐ×cos(θ) and Fₐ > Fₐ×sin(θ), for acute angles, we have that the least force is required when the force is acting parallel to the plane.
20 m
A projectile is fired from the origin (at y = 0 m) as shown in the diagram. The initial velocity components are Vox = 310 m's and Vov = 26 m s The
projectile reaches maximum height at point P. then it falls and strikes the ground at point Q which is 20 m below the launch point. What is the horizontal
distance that the projectile travels (labeled x in the diagram)?
O 1.3 km
700 m
O 32 km
O 870 m
O 1.9 km
Answer:
1.9 km
Explanation:
The equation for vertical motion is ...
h(t) = -4.9t^2 +26t +20
This will have a zero near t = 5.988 seconds.*
The horizontal distance traveled in that time is ...
(310 m/s)(5.988 s) ≈ 1856 m ≈ 1.9 km
_____
* The root of a quadratic can be found numerous ways. We choose the quick and easy: let a graphing calculator show it to you.
What is Cognitive Behavioural Therapy?
Answer:-
Cognitive behavioral therapy (CBT) is a form of psychological treatment that has been demonstrated to be effective for a range of problems including depression, anxiety disorders, alcohol and drug use problems, marital problems, eating disorders and severe mental illness. CBT leads to significant improvement in functioning and quality of life.
Hope this help :)
And can u give brainliest.
The goal of cognitive behavioral therapy (CBT), a type of psychotherapy, is to alter unhelpful thought and behavior patterns.
What is Cognitive Behavioural Therapy?Cognitive Behavioral Therapy (CBT) is a form of psychotherapy that focuses on changing negative patterns of thinking and behavior. It is a goal-oriented and structured therapy that aims to help individuals identify and modify their thoughts and behaviors that may be contributing to psychological distress.
CBT is based on the idea that the way people think about a situation affects how they feel and how they behave. In CBT, therapists work with clients to identify and challenge negative and irrational thoughts and beliefs, and replace them with more realistic and positive ones. This can lead to improved mood and behavior.
CBT is a collaborative therapy, where the therapist and client work together to set goals and develop strategies to achieve them. CBT typically involves a specific number of sessions, with the number and frequency of sessions varying depending on the individual's needs and goals.
CBT has been found to be effective in treating a wide range of mental health issues, including anxiety disorders, depression, post-traumatic stress disorder, obsessive-compulsive disorder, and eating disorders. It is often used in combination with other treatments, such as medication, and can also be adapted for use with children and adolescents.
Therefore, To change unhelpful thought and behavior patterns is the aim of cognitive behavior therapy (CBT), a type of psychotherapy.
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A man wishes to lift a stone weighing 1440 N, using a first-class lever that measures 5 meters. What force should it perform if the fulcrum is 150 cm from the stone. *
Answer:
3360 N
Explanation:
In a first-class lever, the effort force and load force are on opposite sides of the fulcrum.
The lever is 5 m long. The load force is 1.50 m from the fulcrum, so the effort force must be 3.50 m from the fulcrum.
The torques are equal:
Fr = Fr
(1440 N) (3.5 m) = F (1.5 m)
F = 3360 N
This mathematical model describes the changes that occur in a sample of
water as its temperature increases. Use this model to predict what will
happen to the motion of the molecules in a sample of water that is being
heated from 50° to 100°C.
200°C
vaporization
150°C
melting
100°C
Temperature (°C)
water vapor
50°C
liquid water
0°C-
--50°C
10
20
ice
30
Time (min)
40
50
60
70
O A. The motion will change very little.
O B. The molecules will stop moving.
O C. The movement of the molecules will gradually decrease.
O D. The movement of the molecules will gradually increase.
The correct answer is D. The movement of the molecules will gradually increase.
Explanation:
At the beginning of the model the state of matter of the water is solid, in this, particles have a defined arrangement and are together, which stops particles from moving freely and only allows them to vibrate. However, as the substance is heated the thermal energy (heat) increases in the sample, this causes particles to move more and the arrangement of it changes. Due to this, when the ice melts and there is liquid water particles move more than in solid states, which makes ice lacks a defined shape. Moreover, as the heat continues to increase the thermal and kinetic energy (movement) increases, indeed in gas state (water vapor) particles will move freely. This means the movement or kinetic energy in particles gradually increases in the model.
Answer: D
Explanation:
What is at the very center of our galaxy? This question is difficult to answer because the center is completely obscured to our eyes behind a large amount of dust. On the basis of what you know about dust from previous chapters, what can be done to improve our view of the galaxy’s center?
Answer:
The answer is "Observe it in the infrared"
Explanation:
The infrared observatory is a device, which helps to track but also fix thermal light from sources out and the front of Earth's atmosphere like nebulae, young stars, and dust and gas in several other galaxies.
The very center of our galaxy is like a star cluster is situated in the central of our universe across the Milky Way supermassive, and the central black hole, around 4 million times our sun's mass.
The main super black hole named the Sagittarius A-star has been located in the nucleus of the galaxy, that's why in this question "Observe it in the infrared" is the correct answer.
This is a form of energy representing the motion of the molecules which make up an object. A. Thermal Energy B. Kinetic Energy C. Gravitational Potential Energy D. Chemical Potential Energy
Answer:
Kinetic energy.
Explanation:
There are many kinds of energy. Some of them are kinetic energy, potential energy, thermal energy etc. The energy that shows the motion of the object is called its kinetic energy.Also, the sum of kinetic energy and the gravitational potential energy is called mechanical energy. Out of the given options, kinetic energy is the form of energy that represents the motion of the molecules which make up an object. Hence, the correct option is (B).Is it vaccum at a height of 75,000 ft?
Answer:
No. A vacuum does not exist at an altitude of 75,000 ft
Explanation:
There is naturally a decrease in air pressure as one goes higher into the atmosphere. However, vacuum conditions are not actually present within the atmosphere as there are still significant amounts of gases even at really high altitudes.
To prove this we know that planes cannot fly in a vacuum, because they need to burn air in order to gain propulsion from their engines.
One military plane - the SR-71 flew at about 90,000 feet.
This is a lot higher than 75,000 feet. For it to be able to at that altitude, it means that there was a significant quantity of air left even at 90,000 feet.
How do you find the rest mass (kg) of a 3.1 eV electron?
Answer:
Explanation:
The rest energy of any substance is defined by the Einstein's mass energy equivalence relation. Thus the rest mass of a electron is 9.11x10^-31 kg. The speed of light is 299,792,458 m/s. Thus multiplying the square of speed of light with the rest mass of electron gives the rest energy of the electron.
Which prefix indicates the smallest part of a unit?
O A. Mega-
B. Milli-
O C. Kilo-
O D. Micro-
SUBM
The prefix which indicates the smallest part of a unit D. Micro
What is prefix of a unit ?A unit prefix is that precedes a basic unit of measurement to indicate a multiple or submultiple of the unit .
1 mega = 10^(6)
1 milli = 10^(-3)
1 kilo = 10^(2)
1 micro = 10 ^ (-6)
out of all above prefix of units d) Micro is the smallest
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Unit of energy density of electric field is a) NC-3 b) JC-3 c) Jm-3 d)JF
Answer:
the answer is c
Increase in Space Suit Pressure 0.0/3.0 points (graded) If the pressure in a space suit increases, how will each of the following be affected? Flexilibity will: Increase Decrease Stay the same unanswered The required pre-breathe time will: Increase Decrease Stay the same unanswered The mass of the suit will: Increase Decrease Stay the same
Answer:
Flexibility Increases
Pre-breathe time decreases
Mass of suit decreases.
Explanation:
Spacesuits are designed for space shuttles when a person goes to explore the galaxy. The spacesuits shuttle era are pressurized at 4.3 pounds per inch. The gas in the suit is 100% of oxygen and there is more oxygen to breathe when the altitude of 10,000 is reached. This will decrease the breathing time and mass of suit.
Negative ions have _____.
A negaive ion has more electrons bound to it than protons in its nucleus.
On his fishing trip Justin rides in a boat 12 km south. The fish aren’t biting so they go 4 km west. They then follow a school of fish 1 km north. What distance did they cover? What was their displacement?
Answer:
I think the answer is 8km2
Answer:
Distance = 17km
Displacement = 12.6 km
Explanation:
south 12km
west 4km
north 1km
Total distance = 12 + 4 + 1 = 17km
Total displacement = in picture above.
Suppose you are testing a new amusement park roller coaster with an empty car with a mass of 100 kg. One part of the track is a vertical loop with a radius of 12.0 m. At the bottom of the loop (point A), the car has a speed of 25.0 m/s and at the top of the loop (point B), it has a speed of 8.00 m/s. As the car rolls from point A to point B, how much work is done by friction? Use 9.81 m/s2 for the acceleration due to gravity.
Answer:
Explanation:
Gain of kinetic energy + work done by friction = loss of potential energy
= 1 / 2 m ( 25² - 8² ) + work done by friction = m x 9.8 x ( 12 + 12 )
= .5 x 100 x ( 625 - 64 ) + work done by friction = 100 x 9.8 x 24
28050 + work done by friction = 23520
work done by friction = -4530 J
Which of the following statements are true? (mark all that apply)
a) Light is a form of energy.
b) The rate of flow of energy is measured in Watts.
c) White light is made of all the colors of the rainbow and can be split to show them all including shades of gray all the way to black
d) Black is the absence of light.
Answer:
(a) and (b)
Explanation:
Energy is the capacity to do work, and exists in various forms. These forms can be converted one to another by the use of appropriate means. Some examples are sound, mechanical, solar, light, which causes the sensation of vision, etc. energy is measured in Joules (J).
The rate of transfer of energy is called power.
i.e Power = [tex]\frac{energy}{time}[/tex]
It is measured in Watts (W).
When a white light is disperses into its colors, gray and black are not part of the colors. And a black sometimes could be as a result of the absorption of all other colors of light.
Suppose the position of an object moving in a straight line is given by s (t )equals 5 t cubed minus 2 t squared plus 9. Find the instantaneous velocity when tequals7.
Answer:
Explanation:
s(t) = 5t³-2t²+9
Instantaneous velocity v = ds / dt
v = ds/dt = 15t²-4t
Putting t = 7
v = 15 x 7² - 4 x 7
= 707
Instantaneous velocity at t = 7
is 707 unit .
Some students set up a circuit and decided to measure the voltage at different points around
the circuit. (Assume all the resistance are the same.)
What was the voltage reading shown on Voltmeter 1,2 and 3? If you know the answer please explain bc I have no idea :)
Answer:
V₁ = 6 V , V₂ = V₃ = 3 V
Explanation:
To solve this circuit we must remember that there are two fundamental types of construction in series and parallel.
* a serial circuit there is only one path for current
in this circuit the constant current in the entire circuit and the voltage is the sum of the voltage of each term
* Parallel circuit in this there are two or more paths for the current
in this circuit the voltage is constant and the east is divided between each branch
with these principles let's analyze the proposed circuit
The DC battery is in parallel with resistor R1 and the equivalent of the other branch,
as in a parallel circuit the voltage is constant
V₁ = 6 V
in the other branch (23) it forms a series construction, where the current is constant
6 = iR₂ + iR₃
as they indicate that each resistance has the same value
6 = 2 iR
V = V₂ = V₃ = 3 V
A loudspeaker at the origin emits a 130 Hz tone on a day when the speed of sound is 340 m/s. The phase difference between two points on the x-axis is 5.6 rad.What is the distance between these two points
Answer:
distance between two points having phase difference 5.6 rad is
Φ = 2.33 m
Explanation:
given
frequency, f = 130Hz
speed of sound in air, v = 340m/s
distance between two crust or through with phase difference 2[tex]\pi[/tex] = λ (wavelength)
phase difference = 5.6 rad
note: distance between two points having a phase difference = [tex]\frac{ \lambda }{2\pi }[/tex]
∴ distance between two points having phase difference of 5.6 rad is = [tex]\frac{ \lambda }{2\pi }[/tex] ×5.6
Recall
v = f × λ
speed = frequency × wavelength
wavelength = speed/frequency
λ = v/f
λ = 340/130 = 2.615 m
∴ distance between two points having phase difference 5.6 rad is = [tex]\frac{ 2.615 }{2\pi }[/tex] ×5.6 = 2.33 m
Two kilograms of nitrogen (N2) at 25°C is contained in a 0.62 m3 rigid tank. This tank is connected by a valve to a 0.16 m3 rigid tank containing 0.8 kg of oxygen (O2) at 127°C. The valve is opened, and the gases are allowed to mix, achieving an equilibrium state at 87°C.
initial pressures of N2 is 5.7293 bar and O2 is 5.2 bar.
the final pressure is 6.44 bar.
the magnitude of the heat transfer for the process is 162.8 kJ, and the direction of energy flow is going in.
What is the entropy change for the mixing process, in kJ/K?
Answer:
Explanation:
For entropy change the formula is
ΔS = ΔQ / T
ΔQ = Δ H
ΔS = Δ H / T
Given
Δ H = + 162.8 kJ
We can take equilibrium temperature as average temperature of the whole process
So, T = 273 + 87 = 360 K
ΔS = Δ H / T
= 162.8 kJ / 360
= + 0.508 kJ / K .
When the magnitude of the heat transfer for the process is 162.8 kJ, Then the entropy change for the mixing process, in kJ/K is = + 0.508 kJ / K
What is Entropy change?
For The entropy change, the formula is
Then ΔS = ΔQ / T
After that ΔQ = Δ H
Then ΔS = Δ H / T
Given as per question are:
Then Δ H = + 162.8 kJ
Now We can take equilibrium temperature as average temperature of the whole process are:
So, T is = 273 + 87 = 360 K
Then ΔS = Δ H / T
After that = 162.8 kJ / 360
Therefore, = + 0.508 kJ / K.
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define motion also justify that rest and motion are related terms
Answer;
Motion: A body is said to be in motion if it changes its position with respect to its surroundings.
Explanation:
Rest and motion are the relative terms because they depend on the observer's frame of reference. So if two different observers are not at rest with respect to each other, then they too get different results when they observe the motion or rest of a body .
one example for each. Rest: If a body does not change its position with respect to its surroundings, the body is said to be at rest. ... Motion: A body is said to be in motion if it changes its position with respect to its surroundings.
A body moves in a straight line. At time, it's acceleration is given by a = 12t + 1. When t =0, the velocity of the body v is 2 metres per second and its displacement from the origin s is 0.
1. Express v and s in terms of t.
2. Determine velocity and displacement of the body after 3 seconds.
Answer:
v = 6t² + t + 2, s = 2t³ + ½ t² + 2t
59 m/s, 64.5 m
Explanation:
a = 12t + 1
v = ∫ a dt
v = 6t² + t + C
At t = 0, v = 2.
2 = 6(0)² + (0) + C
2 = C
Therefore, v = 6t² + t + 2.
s = ∫ v dt
s = 2t³ + ½ t² + 2t + C
At t = 0, s = 0.
0 = 2(0)³ + ½ (0)² + 2(0) + C
0 = C
Therefore, s = 2t³ + ½ t² + 2t.
At t = 3:
v = 6(3)² + (3) + 2 = 59
s = 2(3)³ + ½ (3)² + 2(3) = 64.5
What is electromagnet and list the types of electromagnet.
Answer:
radio waves, micro wave, x-rays
Explanation:
Explanation:
A MAGNET IN WHICH MAGNETIC FIELD IS PRODUCED BY ELECTRIC CURRENT IS CALLED ELECTROMAGNET.
THE ELECTROMAGNETS ARE HAVE 3 TYPES. THERE ARE:
◇ ROBUST ONES
◇ THE SUPERCONDUCTORS
◇ HYBRIDS.
EXAMPLES OF ELECTROMAGNETS: RADIO WAVES, MICROWAVE, X-RAYS. HOPE IT HELP...❤❤Energy of the fossil fuels is also derived from solar energy. Give reason.
Answer:
Explanation:
All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun
what is the meaning of physics
Answer:
the branch of science concerned with the nature and properties of matter and energy
PLEASE HELP!!!! i will give brainliest to the first person...
Answer: Fossil fuels power the machine that shakes the tree so the apples fall to the ground
Explanation: most machines are powered by fossil fuels
A car engine burns gas at 495 K and exhausts to the air at 293 K. What is the highest possible efficiency it could have?
(NO UNIT)
Answer:
59.19%
Explanation:
Step 1:
Data obtained from the question. This include the following:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Step 2:
Determination of the efficiency of the engine.
Efficiency is simply defined as the ratio of output to input times 100. Mathematically, it is expressed as:
Efficiency = output /input x 100
With the above formula, we can calculate the efficiency of the engine as follow:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Efficiency = output /input x 100
Efficiency = 293/495 x 100
Efficiency = 59.19%
Therefore, the efficiency of the engine is 59.19%
Answer:
0.41
Explanation:
Trust me bro
What is difference between gravity and gravitational force
gravity means that is not a force but the gravitational force is a force
For example we call the earth has a gravitational force but on moon we say that it doesn't have gravity
Answer:
Gravity is the Earth’s pull on a body, lying on near the surface of the Earth.
Gravitational force is the force of attraction acting between any two bodies.
A constant force of 230 N is applied to a 24 kg block of concrete for 25 seconds.
a. What is the final speed of the block if it originally at rest
Explanation:
a = f/m
a = 230/24 = 9.58m/s²
t = 25secs
u = 0m/s
v = ?
a = (v - u)/t
9.58 = (v - 0)/25
9.58 x 25 = v
v = 238.75m/s
Which of the following is a TRUE
statement about states of matter?
A. Most matter on Earth exists as a solid, liquid, or gas.
B. Plasma, the fourth state of matter, is abundant on Earth.
C. Matter never changes from a solid to a liquid or a gas.
D. Most matter in the universe is liquid.
The statement that is the most true regarding the states of matter is the first statement.
A. Most matter on Earth exists as a solid, liquid, or gas.
This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.
Therefore, B is incorrect.
C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.
D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.
Matter can be defined as the material substance which constitutes the observable nature. Most matter on Earth exists as a solid, liquid, or gas. Plasma is also the state of matter found in daily life. The correct option is A.
What are states of matter?All the materials which we see in our daily lives are made up of matter. Matter can be classified into different states such as solid, liquid and gas based on the intermolecular forces and the arrangement of particles. All the three states of matter can be converted from one form to another.
The molecules of solid are tightly packed and they have strong intermolecular forces which also has a definite shape and volume. The liquids have weak intermolecular forces than the solids and it acquire the shape of the vessel.
The intermolecular forces in gases are negligible and they do not have any fixed shape or volume.
Thus the correct option is A.
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