Answer:
(a) The parachutist spent 24.84 secs in air
(b) The height the fall begins is 472 m
Explanation:
Here is the complete question:
A parachutist bails out and freely falls 63 m. Then the parachute opens, and thereafter she decelerates at 1.5 m/s2. She reaches the ground with a speed of 3.3 m/s. (a) How long is the parachutist in the air (b) At what height does the fall begin?
Explanation:
From one of the equations of kinematics for free fall
[tex]H = ut - \frac{1}{2}gt^{2}[/tex]
Where H is the height
u is the initial velocity
t is the time
and g is the acceleration due to gravity (Take g = 9.8 m/s2)
Now, we can find the time spent before the parachute opens.
u = 0 m/s (we assume the parachutist starts from rest)
H = - 63 m
∴[tex]-63 = 0(t) - \frac{1}{2}(0.98) t^{2} \\-63 = -4.9 t\\t^{2} = \frac{63}{4.9} \\t^{2} = 12.86\\t = \sqrt{12.86} \\t = 3.59 s[/tex]
This the time spent before the parachute opens
Also from one of the equations of kinematics for free fall
[tex]v = u - gt[/tex]
where v is the final velocity
We can determine the final velocity before the parachute opens and she starts to decelerate
∴[tex]v = - 9.8(3.59)\\v = - 35.18m/s[/tex]
Now, we will calculate the time spent after the parachute opens
From one of the equation of kinematics for linear motion,
[tex]v = u + at[/tex]
Here, the initial velocity will be the final velocity just before the parachute opens, that is
[tex]u = - 35.18 m/s[/tex]
From the question,
[tex]v = - 3.3 m/s[/tex]
[tex]a = 1.5 m/s^{2}[/tex]
We then get
[tex]-3.3 = - 35.18 + (1.5)t[/tex]
[tex]-3.3 + 35.18 = 1.5t\\31.88 = 1.5t[/tex]
[tex]t = \frac{31.88}{1.5}[/tex]
[tex]t = 21.25 secs[/tex]
(a) To determine how long the parachutist is in the air,
That is sum of the time used when falling freely and the time used after the parachute opens
= 3.59 secs + 21.25 secs
24.84 secs
Hence, the parachutist spent 24.84 secs in air
(b) To determine what height the fall begins
First, we will calculate the height from which the parachute opens
From one of the equation of kinematics for linear motion,
[tex]x = ut + \frac{1}{2}at^{2} \\[/tex]
[tex]x = -35.18(21.25) + \frac{1}{2}(1.5)(21.25)^{2} \\x = -747.58 + 338.67\\x = -408.91m\\[/tex]
[tex]x[/tex] ≅ [tex]- 409m[/tex]
Hence, the height the fall begins is 63m + 409m
= 472 m
Scientist Jordan makes a discovery and publishes the results for other scientists to read. Scientist Leesha tries to repeat the experiment and cannot make it work. Her results are also published. Scientist Jordan looks at his data again and finds that the discovery only works under certain conditions. He publishes the change. Now scientist Leesha repeats the new method and finds the same results as Jordan, but another scientist, Winslow, gets different results. What does this story demonstrate? A. that scientific knowledge is impossible to obtain B. that scientific knowledge results from a lot of debate and confirmation C. that scientific knowledge is developed by individual scientists in isolation D. that scientists are really good at arguing
Answer:
Answer choice B!
Explanation:
Study Island work
Answer:A
I DID THIS ON STUDYILSLAND
People hoping to travel to other worlds are faced with huge challenges. One of the biggest is the time required for a journey. The nearest star is 4.1×1016m 4.1 × 10 16 m away. Suppose you had a spacecraft that could accelerate at 1.5 g g for two thirds of a year, then continue at a constant speed. (This is far beyond what can be achieved with any known technology.)How long would it take you to reach the nearest star to earth?
Answer:
It would take 8.22037 hrs away. Wouldn't it?
Explanation:
Because
4.11016
4.11016
15
= 8.22037
Titus drives his jetski a distance of 1000 meters in 7.045 seconds. How fast was he moving in meters per second? How fast was he moving in miles per hour?
Answer:
a) v = 141.9 m/s
b) v = 317.4 miles/h
Explanation:
a) How fast was he moving in meters per second?
[tex] v = \frac{d}{t} = \frac{1000 m}{7.045 s} = 141.9 m/s [/tex]
Hence, the jet ski is moving at 141.9 meters per second.
b) How fast was he moving in miles per hour?
[tex] v = \frac{d}{t} = \frac{1000 m}{7.045 s} = 141.9 m/s*\frac{3600 s}{1 h}*\frac{1 mile}{1609.34 m} = 317.4 miles/h [/tex]
Therefore, the jet ski is moving at 317.4 miles per hour.
I hope it helps you!
It takes a person 22 seconds to swim in a straight line from the south end of
a pool to the north end of the pool, a distance of 28 meters. What is the
swimmer's velocity?
Answer:
1.27 m/s.
Explanation:
The following data were obtained from the question:
Displacement (D) = 28 m
Time (t) = 22 secs
Velocity (v) =?
Velocity is simply defined as the rate of change of displacement of an object with time. It can be represented mathematically as:
Velocity (v) = Displacement (D) /Time (t)
v = D/t
With the above formula, we can obtain the swimmer's velocity as follow:
Displacement (D) = 28 m
Time (t) = 22 secs
Velocity (v) =?
v = D/t
v = 28/22
v = 1.27 m/s
Therefore, the swimmer's velocity is 1.27 m/s.
Answer:
1.3 m/s north
Explanation:
A student walks to school everyday. It takes the student 2 hours to walk the 4 miles to
school. What is the students average speed?
2 miles an hour
4 devided by 2
Answer:
2 miles per hour is the answer
A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in:
A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in: 2 seconds
Answer:
2.4 m
Explanation:
From the question above,
Applying equation of motion,
s = ut+at²/2....................... Equation 1
Where t = time, u = initial velocity, a = acceleration, s = distance.
make s the subject of the equation,
Given: a = 1.8 m/s², t = 2 seconds, u = 0 m/s (from rest)
Substitute these value into equation 1
s = 0(2)+1.8(2²)/2
s = 1.2(4)/2
s = 2.4 m.
Hence she has traveled 2.4 m
Answer:
4.0m/s
Explanation:
I just did this question for school, hopefully this helps!
A satellite’s original velocity is 10,000 m/s. After 60 seconds it s going 5,000 m/s. What is the acceleration? Remember acceleration = (final speed – initial speed) ÷ time .
(p.s i think this is physics? i don't know i just know its science so if anyone can help with this it would be greatly appreciated)
Explanation:
Given that,
Orginal speed, u = 10,000 m/s
Final speed, v = 5,000 m/s
Time, t = 60 s
To find,
Acceleration of the satellite.
The acceleration of an object is equal to the change in its speed divided by time. So,
[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{5000-10000}{60}\\\\a=-83.34\ m/s^2[/tex]
So, the acceleration of the satellite is [tex]83.34\ m/s^2[/tex] and it is deaccelerating.
What disadvantage does floating buoys have when it comes to converting wave energy to electrical energy? A) They generate only minimum amounts of electricity. B) They pose a risk to migrating whales in the ocean. C) They are easily degraded by the salt water. D) The turbulent ocean often breaks these buoys. Grade Results got me messed up my dudes.
Answer:
B
Explanation:
When performing a cranking sound diagnosis, Technician A says that all engines may be prevented from starting by holding the throttle wide open while cranking. Technician B says that an engine may be disabled by removing the fuel pump fuse or relay (if equipped). Who is correct?
Answer:
Technician B
Explanation:
An engine can be disabled by removing the fuel pump fuse or relay if equipped. Therefore, Technician B is correct.
What can make an engine stop working?Engines generally stop suddenly if they suffer from a lack of fuel or sparks. An engine that can stop dead without prior warning and has probably had an instant ignition failure although when it locks solid it's more probably to have seized.
There are two ways to stop a diesel engine, remove the fuel pump fuse or cut off the fuel or the air. The easy way to stop a boat engine is to cut off the air.
The most general reasons for poor engine combustion because of broken valve seals, overused piston rings, holes within cylinders, and forcing air to leak out.
Assuming it's a gasoline-powered vehicle when removing a fuse or breaker for the ignition or fuel injection, the car wouldn't start. An engine can be disabled by cutting off the fuel pump fuse or relay if equipped.
Learn more about engine, here:
https://brainly.com/question/28994705
#SPJ2
NEED HELP ASAP Carlos is analyzing the results of a recent scientific study about gravity. Scientists recorded that the experimental value of gravity was 10.24 m/s² and the general accepted value of gravity is 9.81 m/s². Calculate the percent error of the experimental versus accepted values of gravity. 5.01% 4.38% 2.66% 9.27%
Answer:
4.38 %
Explanation:
Given that,
The experimental value of gravity is 10.24 m/s²
The general accepted value of gravity is 9.81 m/s²
We need to find the percent error of the experimental versus accepted values of gravity.
The formula used to find the percentage error is given by :
[tex]\%=\dfrac{|\text{original value-calculated value}|}{\text{original value}}[/tex]
Putting all the values:
[tex]\%g=\dfrac{|9.81-10.24|}{9.81}\times 100\\\\\%g=4.38 \%[/tex]
So, the percentage error is 4.38 %.
A ferrari advertisement states that a certain car can accelerate from rest to 20 m/s in 7 seconds. Find the car’s average acceleration
Answer:2.9m/s^2
Explanation:
acceleration= final velocity-initial velocity / time
20m/s - 0m/s / 7 seconds
=2.9m/s^2
Melissa and Rory live near a bike trail, 21 km apart. They plan to meet at a park mid-way between their homes. They start from their homes at the same moment, and ride toward each other. Both ride at 7 km/hour. Melissa’s dog Jessie knows this routine. He starts with Melissa, and runs at 18 km/hour toward Rory. When he reaches Rory, he turns around and runs toward Melissa. He reaches Melissa, turns around and runs toward Rory again, and so on, until Melissa and Rory meet. How many kilometers did Jessie run?
Answer:
27km.
Explanation:
Jessie will run for a duration of time, which is the time it takes for Melissa and Rory to meet each other.
Together combined, Melissa and Rory runs at 14km/h. The bike trail is 21km, so it will take 1.5 hours.
Jessie runs at 18km/h, so Jessie will run 18 * 1.5 = 27km.
A clever octopus swims 8 1/4km at a speed
of 0.5 km/h. How long does the octopus
take to swim this distance in hours and
minutes
Answer:
33 hours or equivalently: 1980 minutes
Explanation:
Use the formula for movement under constant velocity, as the velocity equal the distance traveled divided by the time it took, and solve for the unknown time (t):
[tex]v=\frac{distance}{t} \\t=\frac{distance}{v} \\t=\frac{8.25\,\,km}{0.5 \,\,km/h} \\t = 33 \,\,h[/tex]
which can also be given in minutes as : 33 x 60 = 1980 minutes
"The most important thing a psychologist can study is how a behavior or thought helps a person navigate the world,
rather than how that thought comes to be or what it is made of."
This viewpoint probably comes from somebody who believes in what historical theoretical approach?
Answer:
Hey there!
This viewpoint probably comes from somebody who believes in the functionalism approach.
Let me know if this helps :)
Plz help it's physics really easy
Answer:
D. there is not enough information to tell
Explanation:
I have already read this in grade five
Technically, there is not enough information to tell, because in your picture, you cut off the last word in the question.
If the last word in the question is "acceleration", then "C" is the correct choice.
If some other word is the last one in the question, then it has to be "D".
4) A force of 500 N acts on an area of 0.05m2. Find the pressure in Pascal.
Answer:
pressure = force ie 500 N divided by area ie 0.05m².
p=f by a
p= 500n divided by 0.05 m²
p= 10,000 pascal
A student is looking at a single-celled organism under a microscope. The presence of which structure would indicate that the cell is eukaryotic? Choose 1 answer: (Choice A) A DNA (Choice B) B Nucleus (Choice C) C Cell membrane (Choice D) D Cytosol
Answer:
B. nucleus
Explanation:
Answer: B
Explanation: A eukaryotic cell has a nucleus, while a prokaryotic cell doesn’t.
what makes a star produce energy
Answer:
Stars produce energy from nuclear reactions, primarily the fusion of hydrogen to form helium. These and other processes in stars have lead to the formation of all the other elements.
Explanation:
Answer:
The answer is C)
Explanation:
C) Nuclear fusion
A cannonball is fired horizontally at the same time a ball being dropped from the same height How do the times it takes them to hit the ground compare?
Answer:
The cannonball and the ball will both take the same amount of time before they hit the ground.
Explanation:
For a ball fired horizontally from a given height, there is only a vertical acceleration on it towards the ground. This acceleration is equal to the acceleration due to gravity (g = 9.81 m/s^2). A ball dropped from a height will also only experience the same vertical acceleration downwards which is also equal to g = 9.81 m/s^2.
Therefore both the cannonball and the ball will take the same amount of time to hit the ground if they are released/fired from the same height.
Is the following sentence true or false? A scientific law attempts to
explain an observed pattern in nature.
Which statement describes a characteristic of most metals?
A.They can be formed into wires.
B.They cannot be shaped by hammering or pounding
C.They are liquid at room temperature
D.They are poor conductors.
Answer:
Answer is A
Explanation:
A on edge
Answer:
A. They can be formed into wires
Explanation:
Metals are also malleable, which means that they can be hammered into very thin sheets without breaking. They are ductile, which means that they can be drawn into wires. When a fresh surface of any metal is exposed, it will be very shiny because it reflects light well. So they can be shaped by hammering or pounding. Metals are not liquids except mercury but most metals are not liquid at room temperature. Metals are actually great conductors/conductibility, which means they have a heat factor in them which most metals do.
Therefore, this shows that A. They can be formed into wires. Is the best choice
Hope this helped :D
Question 6 of 10
A car with a mass of 1,300 kg travels a distance of 200 m as it moves from
one stoplight to the next. At its fastest, the car travels at 20 m/s. What is its
kinetic energy at this point?
A. 520,000 J
B. 2,600 J
C. 260,000 J
D. 13,000 J
Answer: It is c.
Explanation:
260,000 J.
Answer:
C. 260,000
Explanation:
it's not that hard just do the work
i hope this helps
Convert 2.5 MM to micrometers
Please show an explanation.
Answer:
2500 micrometers.
Explanation:
When ever it comes to converting a value into micrometers, you just multiply the length value by 1000.
how do you verify scientific hypothesis?
An object moves at a constant speed of 6 m/s. This means that the object:
Answer:
The object moves 6 m in every second.
Explanation:
When we say something is constant, we simply means that it does not change with time i.e it the same through out irrespective of time.
Now, let us answer the question given above.
An object moving at a constant speed of 6 m/s. Has the following characteristics:
1. The object moves 6 m in every second.
2. The object is not accelerating since it has a constant speed. Therefore, the acceleration of the object is zero.
3. The object is moving as it covers a distance of 6 m in every second.
4. The speed remains the same since the speed of object is constant.
Thus, the right answer to question is: The object moves 6 m in every second.
Does a ball ever bounce back to it's drop height?
Answer: No
Explanation: Once you bounce the ball it will go higher and then it will slowly come back down
Answer:
depends the material
Explanation:
if its rubber yes for sure
An object begins with a speed of 20 meters per second and slows down to a speed of 10 meters per second over a time of 5 seconds. Calculate the average speed of the object during these 5 seconds.
can someone tell me how to do this please?
Answer:
V = 6 m/s
Explanation:
Given that,
Initial speed of an object is 20 m/s
Final speed of an object is 10 m/s
Time, t = 5 s
We need to find the average speed of the object during these 5 seconds. Let it is equal to V. Here, time is same. The average speed is given by :
[tex]V=\dfrac{x+y}{2}\\\\\text{Putting values}\\\\V=\dfrac{20+10}{5}\\\\V=6\ m/s[/tex]
So, the average speed of the object is 6 m/s.
Which psychological perspective can be used to diagnose genetic mental disorders?
Answer:
Most psychiatrists and psychologists use the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) to diagnose mental health disorders.
Answer:?
Explanation:
The energy transferred by a force to a moving object
Answer:
kinetic energy
Explanation:
Question 8
Four materials are put into small containers. These materials
are then moved from the small containers into larger
containers. Which material will spread out to completely fill
a larger container?
O air
oice
O sand
water
Answer:
Air
Explanation:
Matter exists in three states namely; solid, liquid and gas. These three states contain molecules/particles that behave differently from one another. The particles of gas are scattered in such a way that they move randomly in a fast motion. This causes the ability of gas particles to diffuse in an open space i.e. spread quickly
In the options of materials given in this question, AIR represents a gaseous substance, hence, it is made up of particles that move rapidly in a random manner. This will cause it to spread out (diffuse) to completely fill a larger container it is placed in.