Answer:
v = √2gh
v = 7 m / s
Explanation:
For this exercise we can use the law of conservation of energy
starting point. In the roof
Em₀ = U = m g h
final point. On the floor
Em_f = K = ½ m v²
as there is no friction, the energy is conserved
Em₀ = Em_f
m g h = ½ m v²
v = √2gh
In the exercise the height of the ceiling is not indicated, but in general the height of the ceiling of a house is h = 2.5 m
v = √ (2 9.8 2.5)
v = 7 m / s
A car passes through a 20 meter speed trap in 5 seconds. How far will it go in 100 seconds?
Answer:
It will be 400 meters.
Explanation:
100 total seconds divided by 5 second interval equals 20.
Then 20 intervals multiplied by 20 meters per interval equals 400 meters.
difference between universal law of gravitation and acceleration due to gravity
Explanation:
The acceleration on an object due to the gravity of any massive body is represented by g (small g). The force of attraction between any two unit masses separated by unit distance is called universal gravitational constant denoted by G(capital g). The relation between G and g is not proportional. That means they are independent entities.
G and g
In physics, G and g can be related mathematically as –
\(g=\frac{GM}{R^{2}}\)
Where,
1=g is the acceleration due to the gravity of any massive body measured in m/s2.
2=G is the universal gravitational constant measured in Nm2/kg2.
3=R is the radius of the massive body measured in km.
4=M is the mass of the massive body measured in Kg.
During a biology lab, students use a small knife called a scalpel to examine a large cricket. One student is accidentally cut by the scalpel. Which steps must be taken to ensure this student's safety? quickly yelling to the lab instructor putting on gloves before treating the cut using disinfectant on the cut applying a bandage immediately calmly telling the lab instructor washing hands after treating the cut
Answer:
Take the following steps
putting on gloves before treating the cut
using disinfectant on the cut
calmly telling the lab instructor
washing hands after treating the cut scalpel safety rules scalpel
use in lab how to use a scalpel safely how to use a scalpel correctly handling sharp objects sharp instrument safety sharp object safety rules safe handling and disposal of sharps policy
Report inappropriate predictions
A car goes from 40 m/s to 30 m/s in 5 sec. What is its acceleration?
Please help me
The car's average acceleration is
a (ave) = (30 m/s - 40 m/s)/(5 s) = -2 m/s^2
(That is, divide the change in velocity by the time it takes for the change to take place.)
If acceleration is constant, then it is equal to the average acceleration.
A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6 s. What was the height from which the ball was dropped
Answer:
Total height (s) = 176.4 m
Explanation:
Given:
Initial velocity (u) = 0 m/s
Time taken (t) = 6 sec
Acceleration due to gravity = 9.8 m/s²
Find:
Total height (s)
Computation:
s = ut + [1/2]gt²
s = (0)(6) + [1/2][9.8][6²]
s = 176.4 m
Total height (s) = 176.4 m
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
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
a cart rolls down a track. it starts from rest and attains a speed of 2.7 m/s in 3 s, what is the acceleration and distance traveled?
Answer:
Acceleration and the distance traveled are 0.9 m/s² and 4.05 m
Explanation:
Given that,
Initail speed, u = 0
Final speed, v = 2.7 m/s
Time, t = 3 s
To find,
The acceleration and distance traveled.
Solution,
Acceleration is change in speed per unit time
[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{2.7-0}{3}\\\\a=0.9\ m/s^2[/tex]
Let s is the distance,
[tex]d=ut+\dfrac{1}{2}at^2\\\\\because u=0\\\\d=0+\dfrac{1}{2}\times 0.9\times 3^2\\\\d=4.05\ m[/tex]
So, acceleration and the distance traveled are 0.9 m/s² and 4.05 m
PLEASE HELP WILL NAME BRAINLIEST!! An object is dropped from rest. What is its instantaneous speed when it has been in motion for 4 s? The acceleration of gravity is 9.8 m/s^2 Answer in units of m/s.
Explanation:
Using kinematics,
t = 4s
u = 0m/s
a = 9.8m/s^2
Therefore v = u + at = 0 + (4)(9.8) = 39.2m/s.
Which of the following is a hypothesis?
A. Squid sometimes squirt ink.
B. What is a reason for squid to squirt ink?
C. If a squid is attacked by a predator, it will squirt ink.
D. All of the evidence accumulated by scientists over many years
shows that squid squirt ink to defend themselves.
Answer:
C
Explanation:
Hypothesis is one of the science methods. Hypothesis is the same as guessing. It's a scientific method that precedes observations.
According to the question asking that Which of the following is a hypothesis ?
The correct option is C which is
If a squid is attacked by a predator, it will squirt ink
It is an hypothesis because there is no experimental evidence to back it up.
if the mass is 10 gram and the volume is 7 cubic centimetre,find the density in kilogram per cubic metre
Answer:
1.42
Explanation:
devide 10 by 7
why should we conserve biodiversity
The electrostatic force that a charged particle, q1q1 , exerts on another charged particle, QQ , at a distance r1r1 , is FF . A second charged particle, q2q2 , exerts the same force FF on QQ at half the distance r1r1 . What is the value of q1q1 in relation to q2q2 ?
Answer:
q₁ / q₂ = 4
Explanation:
In this exercise we must use Coulomb's law
F = k q₁q₂ / r²
For this case the electric force is
F = k q₁ Q / r₁²
indicate that another particle q₂ has the same force on Q, but for r₂ = r₁ /2
F = k q₂ Q / r₂²
we equate the two equations
q₁Q / r₁² = q₂ Q / r₂²
we substitute r₂
q₁Q / r₁² = q₂ Q / (r₁/2)²
q₁ = q₂ 4
the relationship between the two charges is
q₁ / q₂ = 4
Your friend's car is stuck in the snow. You push very hard and become very 1 tired but the car won't move. Did you do work?
Yes, work was done
No, work wasn't done
Answer:
Yes you worked
Explanation:
You may have not seen a good outcome but you did put effort in.
When a force is applied on the car and it doesn't move then it simply means
work wasn't done.
The formula for work is given below:
Work = Force ₓ Displacement
For work to have been done , the applied force must cause the object to
change its position(displacement).
In situations where the force applied doesn't cause a change in position then work can't be calculated. This means no work was done on the car despite the applied force causing him to be tired.
Read more on https://brainly.com/question/19746065
How far away is mars from the sun?
Answer:
From an average distance of 142 million miles (228 million kilometers), Mars is 1.5 astronomical units away from the Sun.
Mars is four planets away from the sun.
(Here is a pic as well, hopefully it helps!)
Convert 183cm to meters
Pls show the work
Answer:
1.83 meters
Explanation:
1 meter = 100 cm
183cm/100cm= 1.83 meters
Why do u think women basketball is not as popular as men’s basketball
Answer: Look, the main difference between men's and women's college basketball is the attention the programs and players get. The women's ball is slightly smaller than the men's ball. ... Men get a thirty-five-second shot clock, while women only get a thirty-second shot clock.
How to represent milligram in kilogram by standard formula?
Answer:
0.000001 kg
Explanation:
because 1 kg equal 1,000,000 milligrams
we take [tex]\frac{1}{1,000,000}[/tex] which equals 0.000001 kg
Find the dimensions [V] of volume. Express your answer as powers of length ( l), mass ( m), and time ( t).
Answer:
Volume equals to thrice the length. [tex][V] = [L]\times [L]\times [L][/tex]
Explanation:
Dimensionally speaking, volume equals to thrice the length. That is:
[tex][V] = [L]\times [L]\times [L][/tex]
What is the maximum energy that can be transferred to an electron in a hard collision by a 25 MeV
a) Electron (according to convention)
b) Positron
c) Proton
d) Alpha particle
Answer:
Electrons
Explanation:
The electrons are called the subatomic particles. The electrons have one of the symbol of e-and β-. The electrons are the first generation of the Lepton particles. These are generally describe the elementary particles. These particles do not have components and substructure.
Like all other elements the electrons also exhibits some types of properties. These electrons also hit with another particles and start to diffracted in different direction like lights.
The wave property of the electrons can be observed with the help of experiment.
A 25.0-mL aliquot of an aqueous quinine solution was diluted to 50.0 mL and found to have an absorbance of 0.656 at 348 nm when measured in a 2.50-cm cell.A second 25.0-mL aliquot was mixed with 10.00 mL of a solution containing 25.7 ppm of quinine; after dilution to 50.0 mL, this solution had an absorbance of 0.976 (2.50-cm cell). Calculate the concentration of quinine in parts per million in the sample.
Answer:
The value is [tex]C = 21.07 ppm[/tex]
Explanation:
From the question we are told that
The volume of the first aliquot is [tex]V_a1 = 25.0 \ mL[/tex]
The volume after dilution is [tex]V_A = 50.0mL[/tex]
The Absorbance of the first solution is [tex]A_1 = 0.656[/tex]
The wavelength at which the absorbance occurred is [tex]\lambda _1 = 348 nm = 348*10^{-9} \ m[/tex]
The length of the cell [tex]l = 2.50 \ cm[/tex]
The volume the second aliquot is [tex]V_{a2} = 25.0 \ mL[/tex]
The volume of the solution it was mixed with is [tex]V_s = 10.00mL[/tex]
The concentration of quinine in the 10 mL solution [tex]Z = 25.7ppm[/tex]
The volume of the second solution after dilution is [tex]V_d = 50.0 mL[/tex]
The absorbance of the second solution is [tex]A_2 = 0.976[/tex]
Generally the concentration of quinine is mathematically represented as
[tex]C = \frac{A_1 *Z * V_s }{(A_2 -A_1) V_{a2}}[/tex]
=> [tex]C = \frac{ 0.656 * 25.7 * 10.0}{ (0.976 - 0.656) * 25}[/tex]
=> [tex]C = 21.07 ppm[/tex]
How many microseconds are equal to 4.2 ks?
which statement is a Hypothesis? A: Most of the earthworms moved to the shaded area during experiment. B: If an earthworm is given a choice,its will move toward darkness rather than light. C: The earthworms must all be the species. D: Do earthworms prefer bright light or darkness.
Answer:
B
Explanation:
It's saying what you think
Answer:
B.
Explanation:
You don't learn any movement concepts until high school.
Answer:
true
Explanation:
Answer:
yes
Explanation:
you don't learn it until high school
If an object covers a total distance of 20 meters in 4 seconds. What is its average speed?
O 80 m/s
O 0.2 m/s
O 5 m/s
0 24 m/s
What makes scientific investigations similar to other types of investigations?
tions?
What makes scientific inuartia
Answer:
All investigations share steps of the scientific method, such as asking a question, conducting research, or analyzing data. The differences between investigations are usually related to what's being examined and the order of the steps followed.
In a criminal investigation, facts are collected about a crime that has already happened. While there are individual tests that can be done on certain types of evidence, there isn't an experiment to test every part of a crime. It can also be difficult to control all factors in a crime scene in order to test one variable at a time. Usually, there are so many variables and missing facts in a crime that a hypothesis and conclusion are hard to determine.
Explanation:
hope it helps <3
All types of investigation involve the steps of the scientific method, such as asking questions, researching, analyzing data, etc.
What are scientific investigations?The research methods and techniques that can be used in order to develop hypotheses, conduct experiments, analyze data, and draw conclusions are called scientific investigations.
The evidence does not give enough solutions but it can lead to new issues for investigation. The methods that can be used by scientists to do scientific investigations involve scientific methods. The steps utilized by scientists to conduct the scientific investigation include:
Scientific investigation starts with an observation. After observing unusual we commonly question ourselves.
A hypothesis can be described as the possible answer to any scientific question. The hypothesis is logical still it can be falsifiable. The results of the test whether the evidence agrees with the prediction and supports the hypothesis or not to create a conclusion.
Learn more about scientific investigations, here:
https://brainly.com/question/8386821
#SPJ2
give some examples of applications that resulted from work done by physicists
Example reuikfur2skied
The skid marks left by the decelerating jet-powered car The Spirit of America were 9.60 km long. If the car's acceleration was -2.00 m/s2, what was the car's initial velocity.
Answer:
The car's initial velocity is 195.96 m/s
Explanation:
Given;
the length of the mark, x = 9.6 km = 9600 m
acceleration of the car, a = -2 m/s²
Apply the kinematic equation below
v² = u² + 2ax
where;
v is the final velocity = 0
u is the initial velocity
simplify the equation and you will obtain;
0 = u² + 2ax
0 = u² + 2(-2)(9600)
0 = u² - 38400
u² = 38400
u = √38400
u = 195.96 m/s
Therefore, the car's initial velocity is 195.96 m/s
both nuclear fusion and nuclear fission reactions____
Answer:
releases large amounts of energy
Explanation:
If a NASCAR driver is driving around a track, and he travels 600 miles in 3 hours, what is his average speed in miles per hour (mph)? __________ mph
Answer:
200 mph.
Explanation:
If a NASCAR driver travels 600 miles in 3 hours, the way to calculate the speed at which the car is driving comes from dividing the distance factor by the time factor.
Thus, we must divide 600 by 3 (600/3), which gives 200 as result. Thus, if in 3 hours he travels 600 miles, in one hour he will travel 200 miles, which means that his average speed is 200 mph.
Submit the assignment following the instructions in the lesson assessment 01.05 measuring physical properties
Answer:jeff gordon is a boss
Explanation: i am so cool thats how i know its correct