Answer:
Vf = 11.04 m/s
Explanation:
First, we consider free fall motion with zero initial velocity. Using 2nd equation of motion:
h = Vi t + (1/2)gt²
where,
h = height of bridge = ?
Vi = Initial Speed = 0 m/s
t = time taken = 4.5 s
g = 9.8 m/s²
Therefore,
h = (0 m/s)(4.5 s) + (1/2)(9.8 m/s²)(4.5 s)²
Therefore,
h = 99.225 m
Now, we consider the forced motion when the youth throws the ball with some negative initial energy:
Vi = - Vi
t = 3 s
h = 99.225 m
Therefore,
99.225 m = - Vi(3 s) + (1/2)(9.8 m/s²)(3 s)²
Vi = (- 99.225 m + 44.145 m)/3 s
Vi = - 18.36 m/s
Now, we use this in 1st equation of motion for final velocity:
Vf = Vi + gt
Vf = -18.36 m/s + (9.8 m/s²)(3 s)
Therefore,
Vf = 11.04 m/s
Jen had an average speed of 2.5 m/s when hopping on one foot. If she hopped for 5.0 seconds, for what distance was she hopping?
Explanation:
distance
speed =_________
time
distance = speed × time
= 2.5 × 5.0
distance = 12.5 m
Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the
material.
We have that for the Question "Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the material." it can be said that
From the question we are told
Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the material.
Generally the equation for the index of refraction is mathematically given as
[tex]n=\frac{C}{v}\\\\Therefore\\\\n=\frac{3*10^8}{2.5 * 10 }\\\\n=12000000\\\\[/tex]
Therefore
The index of refraction of the material is
n=12000000
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Can you hear sounds from space or not? Why or Why not?
You are making s'mores with a friend. When you heat the marshmallow over the fire, what happens to the volume of the air bubbles inside the marshmallows? *
Answer:
Heat was trapped within the marshmallow.
Explanation:
Increasing temperatures make air contained within the marshmallow extend to fill up more room, causing the versatile sugar combination to spread. Eventually, if there is so much tension? It's small explosion. But take the marshmallow out from the heat, and it's going to deflate even if the extended gelatin does not really recover quickly.
Answer:
Heat gets trapped within the marshmallow.
Explanation:
Which TWO correctly relate the attraction between the particles of a liquid and the temperature at which the liquid changes state?
A. Strong attractions mean the liquid melts at a higher temperature
B. Strong attractions mean the liquid melts at a lower temperature
C. Strong attractions mean the liquid boils at a higher temperature
D. Strong attractions mean the liquid boils at a lower temperature
Answer:
a &c
Explanation:
>3
Attraction between the molecules of a liquid and the temperature at which the liquid changes state is "Strong attractions mean the liquid boils at a higher temperature". The correct option is C
What is Temperature ?Temperature is a physical quantity which measures hotness and coldness of a body. Temperature measures the degree of vibration of molecule in a body. Temperature is measured in centigrade (°C), Fahrenheit (°F) and Kelvin (K) in which Kelvin (K) is a SI unit of temperature. Absolute scale of temperature means Kelvin scale of temperature.
relation between Kelvin(K) and centigrade (°C),
°C= K - 273.15
from equation, 273.15 K means 0 °C, which is freezing point of water (ice).
when we give temperature to the body, its molecule or atom absorbs thermal energy and vibrate about their mean position. Amplitude of vibration get increases as we go on increasing temperature and for higher temperature force of attraction between molecules gets weaker. Hence for higher temperature, due to weaken the force of attraction between molecule, solid goes into liquid state. and further increase in temperature liquid goes into gaseous state.
Liquid has stronger force of attraction than gas and weaker than solid. Strong force of attraction means high temperature should be given to break molecular bonds. Therefore Strong attractions mean the liquid boils at a higher temperature.
Hence option C is correct.
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A satellite was in two separate crashes. In both crashes, the satellite had the same mass. Engineers want to know about the speed and direction of the satellite after the crashes. Why would the crash affect the motion of the satellite, and which crash caused a greater change in motion for the satellite?
Answer & Explanation:
Crashing into the asteroid would cause the satellite to slow down, stop, or reverse direction, because it is a force in the opposite direction to the satellite's motion. Whichever crash was a stronger force would cause it to change motion more. It takes a stronger force to change the velocity of a more massive object.
What is one physical benefit that can be obtained from participating in field events?
A) strengthen balance
B) better sleep pattern
C) increase capacity for learning
D) all of the above
Answer:
D
Explanation:
It does all three
A rocket, initially at rest on the ground, accelerates straight upward from rest with constant (net) acceleration 53.9 m/s2 . The acceleration period lasts for time 6.00 s until the fuel is exhausted. After that, the rocket is in free fall.
Find the maximum height ymax reached by the rocket. Ignore air resistance and assume a constant free-fall acceleration equal to 9.80 m/s2 .
Answer:
maximum height reach by rockect =970.2metre
Explanation:
please help!!! give me a summary on why human population is either good or bad!! thank youu
PLZ HELP ME
1. A stone is thrown horizontally from a cliff 30m high with an initial speed of 20m/s. How far from the cliff does the stone strike the ground?
2. A ball rolls off the edge of a table 1.44m above the floor and strikes the floor at a point 2m horizontally from the edge of the table.
A) What is the time the ball was in the air?
B) What is the initial velocity of the ball?
3. A golfer hits a ball and gives it an initial velocity of 40 m/s, at an angle of 30º above the horizontal.
A) How long does the ball stay in the air?
B) How far horizontally (the range) does the ball travel before hitting the ground?
Answer:
1. The stone will strike the ground 49.46 m from the base of the cliff
2. A) Approximately 0.542 seconds
B) Approximately 3.69 m/s
3. A) The time the ball spends in the air is approximately 4.0775 s
B) The horizontal range is approximately 141.25 m.
Explanation:
1. The time it takes the stone to land is given by the equation, t = √(h/(1/2 × g)
∴ t = √(30/(1/2 × 9.81)) ≈ 2.473 seconds
The horizontal distance covered by the stone in that time = 20 × 2.473 ≈ 49.46 m
The stone will strike the ground 49.46 m from the base of the cliff
2. A) The time the ball spends in the air = t = √(h/(1/2 × g)
∴ t = √(1.44/(1/2 × 9.81)) ≈ 0.542 seconds
B) The initial horizontal velocity, u = Horizontal distance/(Time) = 2/0.542 ≈ 3.69 m/s
The initial horizontal velocity ≈ 3.69 m/s
3. A) The time the ball spends in the air is given by the following equation;
t = 2 × u × sin(θ)/g = 2 × 40 × sin(30)/9.81 ≈ 4.0775 s
t ≈ 4.0775 s
B) The horizontal range, R, of the ball is given by the equation for the range of a projectile as follows;
[tex]Range, R = \dfrac{u^2 \times sin (2 \cdot \theta) }{g}[/tex]
Substituting the known values, gives;
[tex]Range, R = \dfrac{40^2 \times sin (2 \times 30^{\circ}) }{9.81} \approx 141.25 \ m[/tex]
The horizontal range ≈ 141.25 m.
A fire is burning in a fireplace. Where is the radiation?
A. You touch warm bricks next to the fireplace
B. You can feel the heat from across the room
C. Heat is rising up from the chimney
Radio stations broadcast signals on two different frequency bands. These are called
Answer:
AM(amplitude modulation) and FM(frequency modulation)
Explanation:
A radio frequency band is a small adjacent section of the radio spectrum frequencies, whereby channels are usually used or set aside to be used.
They are usually of two different bands called AM which is known as amplitude modulation and FM which is known as frequency modulation
What two things must you know to describe the motion of an object? __________________________________________________________________________
Distance is _________________________________________________________________
What is the displacement of a cyclist, who travels 1 mile north, then 1 mile east, and finally 1 mile south? ___________________________
Define speed ________________________________________________________________
How do speed and velocity differ? ______________________________________________
__________________________________________________________________________
How do velocities combine? In opposite directions? ________________________________ In the same direction? ________________________________________________________
A river flows at a velocity of 3 km/h relative to the riverbank. A boat moves upstream at a velocity of 15 km/h relative to the river. What is the velocity of the boat relative to the riverbank? ___________________________________
The rate at which velocity changes is called ________________________
True or false? Acceleration is the result of increases or decreases in speed.
A horse on a carousel that is moving at a constant speed is accelerating because _________________________________________________________________________
True or false? When the final velocity is less than the initial velocity of an object, the acceleration is negative.
The total distance traveled divided by the total time is _______________________
What are some common units for speed (give at least two) _____________ ___________
Define velocity ____________________________________________________________
Define acceleration _________________________________________________________
A quantity that has both magnitude and direction is called a _________________.
WILL MARK BRAINLIEST PLEASE HELP DUE IN 2 MINS
On a distance-time graph speed is a ____________ line and thus a ____________ graph.
On a distance-time graph acceleration is a ___________ line and thus a _______________ graph.
Answer:
velocity is vector Quantity
find acceleration of block and tension in strings if m1 =8kg m2= 4kg and take g=10m/s²
[tex]\sf{m_1}[/tex] = 8kg
[tex]\sf{m_2}[/tex] = 4kg
g = 10m/s²
[tex]\large\bold{\underline{\underline{To \: Find:-}}}[/tex]→Acceleration of block
→Tension in strings
[tex]\large\bold{\underline{\underline{Solution:-}}}[/tex]Let, the two equation will be ,
[tex]\leadsto[/tex] 8g - T = 8a ..... Equation no (1)
[tex]\leadsto[/tex] T - 4g = 4a ..... Equation no (2)
Putting the value of equation no (1) and (2) we get,
[tex]\implies[/tex] 4g = 12a
[tex]\implies[/tex] 4 × 10 = 12a
[tex]\implies[/tex] 40 = 12a
[tex]\implies[/tex] a = [tex]\sf\dfrac{\cancel{40}}{\cancel{12}}[/tex]
[tex]\dashrightarrow[/tex] a = [tex]\dfrac{10}{3}[/tex]
Again, we have to putting the value of a in the equation no (2) we get,
[tex]\implies[/tex] T - 4g = 4 × [tex]\dfrac{10}{3}[/tex]
[tex]\implies[/tex] T - 4 × 10 = 4 × [tex]\dfrac{10}{3}[/tex]
[tex]\implies[/tex] T - 40 = [tex]\dfrac{40}{3}[/tex]
[tex]\implies[/tex] T = [tex]\dfrac{40}{3}[/tex] + 40
[tex]\implies[/tex] T = [tex]\dfrac{40 + 120}{3}[/tex]
[tex]\dashrightarrow[/tex] T = [tex]\dfrac{160}{3}[/tex] N
[tex]\therefore[/tex] Acceleration of block = [tex]\dfrac{10}{3}[/tex] m/s².
And, Tension in strings = [tex]\dfrac{160}{3}[/tex] N
If Newton's third law was true, then why does a table move when I push it? If the table exerted the same amount of force to me, why does it move?
to calculatw the power produced by a force, the size of the force must be known. What else needs to be known to calculate the power
-- The distance the force moved through
-- How long the force lasted
The other thing we need to calculate the power is the "Velocity".
A quantity of labor or work done to be accomplished within a particular period of timeframe is determined as power. It is denoted by "P".According to the given query, we are talking about the relation between Power and Force. Along with simple instances where such an item is moved at continuous speed by a constant force.
The relation can be shown as:
→ [tex]P= Fv[/tex]
where,
P = PowerF = Forcev = VelocityThus the above is the right response.
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Tyler drives 50km north. Tyler then drives back 30km south. What distance did he cover? What was his displacement?
Answer:
80 km is distance and 30km north is displacement
Explanation:
distance= 50+30=80km
displacement= 50-20=30
his displacement is 30km north
When Tyler drives 50 km north and then drives back 30 km south, we have:
1. The distance that he covers is 80 km.
2. Tylor's displacement is 20 km.
1. The distance is a scalar that is given by the sum of the kilometers traveled by Tyler as follows:
[tex] d = d_{1} + d_{2} = 50 km + 30 km = 80 km [/tex]
Hence, the distance traveled by Tyler was 80 km.
2. The displacement is a vector that depends on the direction of travel. Takin the north direction as positive we have:
[tex] x = x_{1} + x_{2} = 50 km + (-30 km) = 20 km [/tex]
Therefore, Tyler's displacement is 20 km.
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If you are in a car at a stop sign and then the driver
presses on the gas pedal really hard, which way is the car
accelerating?
Answer:
it wont be because the hand brake would be on
Name all errors and type it again
EZ POINTS CMON
Answer:
you need to capitalize
Explanation:
When Grandpa Joe comes to visit, he tells us stories about when he was in the army with Colonel Jack S. Anderson.
You push against a wall and the wall pushes back on you.
O Newton's 1st Law of Motion
O Newton's 2nd Law of Motion
Newton's 3rd Law of Motion
Answer:
Its the third law of motion.
Explanation:
Newton's third law of motion states that every action has equal and opposite reaction.
400 N of load can be overcome by an effort of 50 N by using a lever. Calculate the mechanical advantage of the lever.
Answer:
load (l)=400N
Effort(E)=50N
mechanical advantage (MA)= load ÷Effort
(ma)=400÷50
(ma)=8
Explanation:
I copy pasted from the answer from the same question. Remember to first check if ur question is there
A generator converts mechanical energy to electrical energy by using a conducting metal loop turning in a...
A. magnetic field
B. Gravitational field
C. Steel sphere
D. Cooper sphere
Answer:
B- Gravitational Field
Explanation:
Have a nice day, hope you get a good grade!
The generator converts mechanical energy to electrical energy by using a conducting metal loop turning in a gravitational field.
What is the gravitational field?In terms of physics, a gravitational field represent the model that should be used for explaining the impact where the massive body should be extended into the space around it. Also, generating the force on the another massive body.
Therefore, based on the above explanation, the correct option is b.
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When the energy of a wave increases, what happens to the amplitude?
Answer:
The energy transported by a wave is directly proportional to the square of the amplitude. So whatever change occurs in the amplitude, the square of that effect impacts the energy. This means that a doubling of the amplitude results in a quadrupling of the energy.
Explanation:
When the energy of a wave increases, the amplitude also increases. This is because the amplitude of the wave is directly proportional to the energy of a wave.
What is the amplitude of a wave?The amplitude of a wave may be defined as the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It is equal to one-half the length of the vibration path.
It is the principle of physics that when the amplitude of the wave is higher, the energy also gets higher. To summarise, waves carry energy. The amount of energy they carry is related to their frequency and their amplitude. The higher the frequency, the more energy, and the higher the amplitude, the more energy.
Therefore, when the energy of a wave increases, the amplitude also increases. This is because the amplitude of the wave is directly proportional to the energy of a wave.
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NEED HELP IS THERE SOMEONE CAN HELP ME PLS :)
What tool of dream analysis says that feelings and urges are hidden inside an event? condensation symbolism projection displacement
Answer:
Condensation
Explanation:
Answer:
Condensation! Hope this helps!!!
Explanation:
Ashley is flying a plane that has to reach a gradient of 360m/km in order to take off and not crash. Her goal is to travel from sea level to an elevation of 1000m at a distance of 2.8km. Calculate the gradient of Ashley’s flight and determine if she will crash!
Answer:
She is likely to crash because her flight gradient is lesser than the flight gradient required gradient to avoid crashing
Explanation:
The given parameters are;
The required gradient of the plane Ashley is flying needs to reach in order to take off and not crash = 360 m/km
The initial elevation of the plane Ashley is flying = Sea level = 0 m
The goal Ashley intends to make = Elevation of 1000 m at 2.8 km. distance
∴ Ashley's goal = Traveling from sea level to 1000 m at 2.8 km horizontal distance
We have;
The gradient = Rate of change of elevation/(Horizontal distance)
Therefore;
The gradient of Ashley's flight = (1000 - 0)/(2.8 - 0) = 357.143 m/km
The gradient of Ashley's flight ≈ 357.143 m/km which is lesser than the required 360 m/km in order to take off and not crash, therefore, she will crash.
Scientists have invented the equipment to harness the power of lighting for energy use. True or false
A 30 kg object has a frictional force of 60 N. It's coefficient of friction must be...?
A) 0.2
B) 2
C) .002
D) 20
mass = 30kg
frictional force = coefficient of friction * (mass * g)
g = 9.8 m/s^2
So:
60N = x * 294 N
x = 60 N / 294 N = 0,2
What are greenhouse gases? Can you name any?
A stunt man launches a car from the edge of a cliff horizontally. If he is launching off a
30-meter high cliff and must hit a mark 268-meters down range, with what speed
must he leave the cliff?
Answer:
All i got to say is that he is dead dead
Explanation: