Answer:
when the ball is at its highest in the air.
Explanation:
I don't know for sure, but when the ball is in the air it has potential energy to fall(or something like that).
2. True or false?
Forensic entomology uses the study of insects to help criminal investigations.
Suppose that a Ferrari and a Porsche begin a race with a moving start, and each moves with constant speed. One lap of the track is 2 km. The Ferrari laps the Porsche after the Porsche has completed 9 laps. If the speed of the Ferrari had been 10 km/h less, the Porsche would have traveled 18 laps before being overtaken. What were the speeds of the two cars?
Answer:
Porsche = 180 kmph
Ferrari = 200 kmph
Explanation:
Given that
The distance of one lap = 2 km
The distance the Ferrari laps the Porsche = 9 laps
The distance the Ferrari will lap the Porsche with 10 km/h less speed = 18 laps
So we say let,
the speed of the Ferrari = S(f),
the speed of the Porsche = S(p), and
the time that lapse before two cars lapped = t
From the question, we're told that
(S(f) * t1) - (S(p) * t1) = 2 km, also
S(p) * t1 = 9 * 2 = 18 km
Referring back to the initial equation
(S(f) * t1) = 2 + (S(p) * t1)
(S(f) * t1) = 2 + 18 = 20 km
Going back to the question again, we're told that
(S(f) - 10) * t₂ - S(p) * t₂ = 2 km
S(p) * t₂ = 18 * 2 = 36 km
So that,
(S(f) - 10) * t₂ = 2 km + S(p) * t₂
(S(f) - 10) * t₂ = 2 + 36 km = 38 km
(S(f) - 10) * t₂ = 38 km
S(p) * t₂ (36 km) = 2 * S(p) * t₁ (18 km),
S(p) * t₂ = 2 * S(p) * t₁, collect like terms
t₂ = 2t₁
(S(f) - 10) * 2t₁ - S(p) * 2t₁ = 2 km
(S(f) - 10) * 2t₁ = 38 km
(S(f) - 10) * 2t₁ = 38 km
2t₁ * S(f) - 2t₁ * 10 = 38 km
S(f) * t₁ = 20 km,
2 * 20 km - 2t₁ * 10 = 38 km
2t₁ * 10 = 2 * 20 km - 38 km
2t₁ * 10 = 2 km
20t₁ = 2 km
t₁ = 2/20 = 0.1 hour = 6 minutes
This means that
S(p) * t₁ = 18 km
S(p) * 0.1 h = 18 km
S(p) = 18 km/0.1 h = 180 km/h
The speed of the Porsche = S = 180 km/h
S(f) * t₁ = 20 km
S(f) × 0.1 h = 20 km
S(f) = 20 km/0.1 h = 200 km/h
The speed of the Ferrari = S = 200 km/h
What President is responsible for eliminating most vending machines from the cafeterias of public schools ?
Answer:president obama
Explanation:Why this is because he took a of mayor Bloomebergs amti obeity book and made new rules for snack foods.
Homogeneous materials look the same throughout even though they contain
different materials.
A. True
B. False
SUBMIT
Answer:
true ig..
Explanation:
Explain which planets have seasons and why some planets have none at all.
Discuss which planet has seasons most similar to earth and why.
Discuss additional factors that some planets have that affect their seasons.
What fact about other planet’s seasons most surprised you and what did you find the most interesting? Why?
Answer:
Some planets have seasons some don't bc of the distance from the sun some of them are too cold or too hot to have seasons
What statements accurately describe sunspots? Check all that apply.
Sunspots are storms on the Sun's surface.
Sunspots are marked by intense magnetic activity.
Sunspots produce solar flares and hot gassy ejections.
Sunspots can affect Earth's climate.
Sunspots are cool areas where the Sun is covered by clouds.
Answer:
sunspots are storms on the Suns surface
Sunspots are marked by intense magnetic activity
Sunspots produce solar flares and hot gassy ejections.
Sunspots can affect Earth’s climate.
Explanation:
I just did this lesson
The statement that describe sunspot is Sunspots are storms on the Sun's surface.
What are sunspot?Sunspot are region of the earth that are more darker than other surfaces. They have temporary spots that are darker because the temperature of that area is cooler than other surfaces. They have a reduced temperature.
Therefore, The statement that describe sunspot is Sunspots are storms on the Sun's surface.
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The path of a projectile fired at an angle above the horizontal is best described as
2. An athlete runs up the stairs of a tall building in 10 s. If she has a mass of 55 KG and the total vertical distance she covers is 8.2 m, what is the average power (in W)developed by her legs?
Answer:
P = 37.0 W (watts)
Explanation:
Using the formula for power :
P = ( kg × m^2/s^2 ) W
given the mass 55kg, the time 10s, and the displacement 8.2m.
55 kg × 8.2^2 / 10^2
55kg × 67.24 / 100
3698.2/100
P = 36.982 ≈ 37.0 W (nearest tenth)
An airplane flying at 119 m/s is accelerated uniformly at the rate of 0.5 m/s2 for 10
seconds. What is its final speed?
Answer:
124m/s
Explanation:
v=u+at
v=119+(0.5×10)
v=119+5
v=124m/s
QUESTION
The strongest Stars used to be called
what?
Answer:
Absolute magnitude
Explanation:
The brightness a star would have if it were at 10 pc from Earth is called Absolute magnitude.
After a wave passes through a medium, particles in the medium
are permanently displaced in a direction opposite to the direction of the wave
remain in the new location
are moved along with the wave
return to the original position
Answer:
D. Return to the original position
Explanation:
I took the test
What causes tides to occur in the ocean?
Waves
Wind
Gravitational pull
Coriolis effect
Answer:
Gravitational pull
Explanation:
The moon pulls the tides
Answer: gravitational pull
Tides are caused by a gravitational pull from the Moon. Ocean/bay tides rise because of this pull for the gravity under the water. This can happen every day up to 6 times.
When an atom gains or loses electrons, it has an electrical charge. It is known as
Answer:
ion
Explanation:
Atoms can gain or lose making them no longer neutral they become charged and it is called ion.
Does time of flight depend on initial speed?
Which could describe the properties of sedimentary rock?
PLASE HELP
DUE TODAY
Answer:
☝ Some of the properties of sedimentary rocks
A power cycle operating between hot and cold reservoirs at 500 K and 300 K, respectively, receives 1000 kJ by heat transfer from the hot reservoir. The magnitude of the energy discharged by heat transfer to the cold reservoir must satisfy
Answer:
The value is [tex]Q_l \ge 600\ k J[/tex]
Explanation:
From the question we are told that
The temperature of hot is [tex]T_h = 500 \ K[/tex]
The temperature of cold is [tex]T_c = 300 \ K[/tex]
The energy received is [tex]E = 1000 \ kJ = 1000 *10^{3 } \ J[/tex]
Generally the maximum thermal efficiency of the engine is mathematically represented as
[tex]\eta = \frac{T_h - T_c}{T_h}[/tex]
=> [tex]\eta = \frac{500 - 300}{500}[/tex]
=> [tex]\eta = 0.4[/tex]
Generally the thermal efficiency of the engine is
[tex]\eta_t = \frac{Q - Q_l}{Q}[/tex]
Here [tex]Q_l[/tex] is the heat energy rejected
Generally the thermal efficiency must be less than or equal to the maximum thermal efficiency
So
[tex]\frac{Q - Q_l}{Q} \le 0.4[/tex]
=> [tex]\frac{1000 *10^{3} - Q_l}{1000 *10^{3} } \le 0.4[/tex]
the change in inequality sign is because [tex]1000*10^{3}[/tex] which was dividing started multiplying
=> [tex]Q_l \ge 1000*10^{3} - 400*10^{-3}[/tex]
=> [tex]Q_l \ge 600*10^{3} \ J[/tex]
=> [tex]Q_l \ge 600\ k J[/tex]
An Astronaut on the Moon drops a rock straight downward from a height of 1.25 meters. If the acceleration of gravity on the Moon is 1.62 meters per second squared, what is the speed of the rock just before it lands?
Answer:
Since the astronaut drops the rock, the initial velocity of the rock is 0 m/s
We are given:
initial velocity (u) = 0 m/s
final velocity (v) = v m/s
acceleration (a) = 1.62 m/s/s
height (h) = 1.25 m
Solving for v:
From the third equation of motion:
v²-u² = 2ah
replacing the variables
v² - (0)² =2 (1.62)(1.25)
v² = 1.62 * 2.5
v² = 4 (approx)
v = √4
v = 2 m/s
The speed of the rock just before it lands is 2 m/s
A stone is thrown vertically upward with the velocity of 25 m/s. How long day
it take to reach the maximum height? Also calculate the height
Answer:
The stone takes 2.55 sec to reach a maximum height of 31.89 m
Explanation:
Vertical Motion
When an object is thrown vertically up with a speed vo, it loses speed because of the effect of the gravity and gains height until the speed is eventually zero. The height attained at that time is called maximum height, and can be calculated as follows:
[tex]\displaystyle h_m=\frac{v_o^2}{2g}[/tex]
Since vo=25 m/s
[tex]\displaystyle h_m=\frac{25^2}{2\cdot 9.8}=31.89\ m[/tex]
Also, the time taken to reach the maximum height is calculated by:
[tex]\displaystyle t_m=\frac{v_o}{g}[/tex]
[tex]\displaystyle t_m=\frac{25}{9.8}=2.55\ s[/tex]
The stone takes 2.55 sec to reach a maximum height of 31.89 m
What is the frequency (n, in Hz) of the photons emitted by a He-Ne laser with a wavelength (l) of 632.8 nm
Answer:
4.741 × 10¹⁴ Hz
Explanation:
Step 1: Given data
Wavelength of the He-Ne laser (l): 632.8 nmFrequency of the He-Ne laser (n): ?Speed of light (c): 3.000 × 10⁸ m/sStep 2: Convert "l" to meters
We will use the conversion factor 1 m = 10⁹ nm.
632.8 nm × (1 m / 10⁹ nm) = 6.328 × 10⁻⁷ m
Step 3: Calculate the frequency of the He-Ne laser
We will use the following expression.
c = l × n
n = c / l
n = (3.000 × 10⁸ m/s) / (6.328 × 10⁻⁷ m)
n = 4.741 × 10¹⁴ s⁻¹ = 4.741 × 10¹⁴ Hz
The Plateau of Tibet is a dry place. Do you think the wide-leafed plant fossils found on the plateau could grow there today? Explain your answer.
No, I dont think that they could grow there now in this day and age becuase the Plateu of Tbiet is very dry and also a little bit dusty. They barely even have grass down there. Wide leaf plants susually grow somewhee like the rainforest where it is warm, sunny, and rainy but in a place like Tibet, I don't think that they would be able to survive there.
Answer:
No. The leaves are similar to those of plants found in lower elevations with plenty of rainfall, like the plants seen at the lower elevations of the Himalayas. Because the Plateau of Tibet has risen over time, it is not likely that these plants could live in these colder climates.
Explanation:
Sample answer from pluto
An airplane is flying at a velocity of 79 m/s eastward relative to the air. Due to a high-pressure region to the north, the velocity of the air relative to the ground is 18 m/s southward. Find the ground speed of the airplane.
Your car is initially at rest when your hit that gas and the car begins to accelerate at a rate of 2.857 m/s/s. The acceleration lasts for 15.5 s. What is the final speed of the car and how much ground does it cover during this acceleration?
Answer:
Vf = 44.56 [m/s]
Explanation:
In order to solve this problem we must use the following expression of kinematics.
[tex]v_{f} = v_{i}+(a*t)[/tex]
where:
Vf = final velocity [m/s]
Vi = initial velocity = 0
a = acceleration = 2.857 [m/s^2]
t = time = 15.5 [s]
Note: the initial velocity is equal to zero as the car begins its movement from rest, or with an initial velocity equal to zero.
Vf = 0 + (2.875*15.5)
Vf = 44.56 [m/s]
Which best describes a difference between laser light and regular light?
Laser light is less concentrated.
Laser light has a beam that spreads out.
O Laser light is made of one specific color.
O Laser light pumps out light particles one at a time.
Answer: the correct answer should be B
Explanation:
The statement that, best describes a difference between laser light and regular light is laser light is made of one specific color.
What is laser light?A laser light is a light produced by a laser
Laser itself, is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.
Difference between laser light and regular lightRegular light is non-directional and inconsistent, while laser light shows directional and highly consistent distribution.Regular light is a mixture of electromagnetic waves of different wavelengths while Laser light is monochrome (one colour).Thus, the statement that, best describes a difference between laser light and regular light is laser light is made of one specific color.
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A car start from rest accelerate uniformly at rate of 2 m/sec2. Its velocity after 5 seconds will be:
Answer:
nononononononononononononnn
Explanation:
Answer:
Read below to understand
Explanation:
acceleration = change in velocity / change in time
(a = v/t)
You have acceleration and time given so you need to rearrange the equation to solve for velocity
V = a * t
V = 2 * 5
Velocity is 10 m/s
Which statement describes earthquakes?
They release energy
They are caused by reduced stress in rocks
They begin at the epicenter
The result for movement on earth’s surface
Answer:
they release energy
Explanation:
An earthquake is the abrupt release of energy from the earth's crust that causes the earth's surface to shake . Thus , seismic waves are produced. The kind and severity of an earthquake are based on the local seismic activity . therefore the correct answer is option A.
What is the equator?The Equator is an imaginary line passing through the middle of a globe. It is equidistant from the North Pole and the South Pole, Its is a horizontal line residing at 0 degrees latitude .
An earthquake is the abrupt release of energy from the earth's crust that causes the earth's surface to shake . Thus, seismic waves are produced. The kind and severity of an earthquake are based on the local seismic activity .
Thus, the correct answer is option A .
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Tell which is the answer
help please
Answer: a constant? im not sure that just sounds like itd be right.
Explanation:
Answer:
b
Explanation:
because he isn't moving
e. A driver speeds up his vehicle while moving up a hill.
Why?
Answer:
For more acceleration
Explanation:
If he is speeding u a hill his car needs more power ecsue its going upward so he will have to speeed to gain more acceleration so his car doesnt fall
A block is attached to one end of a spring with the other end of the spring fixed to a wall. The block is vibrating horizontally on a frictionless surface. If the mass of the block is 4.0 kg, the spring constant is k
Complete Question
A block is attached to one end of a spring with the other end of the spring fixed to a wall. The block is vibrating horizontally on a frictionless surface. If the mass of the block is 4.0 kg, the spring constant is k = 100 N/m, and the maximum distance of the block from the equilibrium position is 20 cm, what is the speed of the block at an instant when it is a distance of 16 cm from the equilibrium position?
Answer:
The velocity is [tex]v = 0.6 \ m/s[/tex]
Explanation:
From the question we are told that
The mass of the block is m = 4.0 kg
The spring constant is k = 100 N/m
The maximum distance of the block from equilibrium position is d = 20 cm =0.20 m
The distance considered is [tex]d_k = 16 \ cm = 0.16 \ m[/tex]
Generally the maximum energy stored in the spring is mathematically represented as
[tex]E = \frac{1}{2} * k * d^2[/tex]
=> [tex]E = \frac{1}{2} *100 * 0.2^2[/tex]
=> [tex]E = 2.0 \ J[/tex]
Gnerally according to the law of energy conservation
The energy maximum energy of the spring = energy of the spring at [tex]d_k[/tex] + energy of the block at [tex]d_k[/tex]
Here energy of the block at [tex]d_k[/tex] is mathematically represented as
[tex]K_1 = \frac{1}{2} mv^2[/tex]
=> [tex]K_1 = \frac{1}{2} * 4* v^2[/tex]
=> [tex]K_1 = 2v^2[/tex]
Generally the energy of the spring at [tex]d_k[/tex] is mathematically represented as
[tex]E_2 =\frac{1}{2} * k * d_k^2[/tex]
=> [tex]E_2 =\frac{1}{2} * 100 * (0.16)^2[/tex]
=> [tex]E_2 =1.28 \ J[/tex]
So
[tex]2.0 = 1.28 + 2v^2[/tex]
=> [tex]v = 0.6 \ m/s[/tex]
Which atmospheric layer gets warmer as altitude increases and contains the ozone layer?
Answer:
stratosphere
Explanation:
In the stratosphere, temperature increases with altitude. The stratosphere contains the ozone layer, which protects the planet from the Sun's harmful UV radiation.
Stratosphere is the atmospheric layer which gets warmer as the altitude increases and contains the ozone layer.
What is Stratosphere?The stratosphere is a layer of the Earth's atmosphere. It is the second layer of the atmosphere as we go upward into the atmosphere height. The troposphere is the lowest layer of the globe, which is present right below the stratosphere. The next higher layer of the atmosphere above the stratosphere is the mesosphere.
In the stratosphere layer, the temperature increases with the increase in the altitude range. The stratosphere layer contains the ozone layer, which works in the protection of the planet from the Sun's harmful ultraviolet radiations which could lead to cancer.
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The Newton unit obtained from
A)Kg.m/s2
B) Kg. m
C) kg/m
D) kg ml
Answer:
Explanation:
The Newtons unit is kg. m/s2
Option A is the correct answer