Answer:
a) Vf = 13.87[m/s]
b) t = 1 [s]
Explanation:
a)
To solve this problem we can use kinematics equations:
[tex]v_{f}^{2}= v_{i}^{2}+(2*g*h)[/tex]
where:
Vf = final velocity [m/s]
Vi = initial velocity = 4 [m/s]
h = elevation = 9 [m]
g = gravity acceleration = 9.81 [m/s^2]
[tex]v_{f}=\sqrt{(4)^{2} +(2*9.81*9)}\\v_{f}=13.87[m/s][/tex]
b)
Now using the next equation we can find the time
[tex]v_{f}=v_{i} +(g*t) \\t = (13.87-4)/9.81\\t=1[s][/tex]
A general contractor drives 5 miles to the hardware store in 10 minutes. He shops for needed tools for 30 minutes, then drives to his customer’s home at an average speed of 45 mph. He arrives 20 minutes later. Calculate the average speed from the time the contractor leaves his office to the time he arrives at his customer’s home.
Given parameters:
Distance to hardware shop = 5 miles
Time to reach hardware shop = 10 minutes
Time spent at the shop = 30 minutes
Average speed to customer home = 45 mph
Time taken for the travel = 20 minutes
Unknown:
Average speed of the contractor = ?
Solution:
Average speed is the total distance covered divided by the total time taken.
Average speed = [tex]\frac{total distance}{total time taken}[/tex]
total distance = distance to hardware shop + distance to customer's home
We do not know the distance to customer's home but we have been given the speed and time, so we can find the distance.
Distance = speed x time
Convert the time to hrs and solve;
60 minutes = 1 hr
20 minutes = [tex]\frac{20}{60} hr[/tex] = [tex]\frac{1}{3} hr[/tex]
So, Distance = 45mph x [tex]\frac{1}{3} hr[/tex] = 15miles
Now;
Total distance = 5 + 15 = 20miles
Total time = time to reach hardware shop + time to reach customer's house
= 10 + 20
= 30 minutes
Convert the time from minutes to hrs;
60 minutes = 1hr
30 minutes = [tex]\frac{30}{60}[/tex] = 0.5hr
So;
Average speed = [tex]\frac{20}{0.5}[/tex] = 40mph
The average speed is 40mph
Have you ever wondered how a vending machine "knows" that you have put in the correct amount of change to purchase a snack or a drink? These machines use coin detectors that determine the mass and the size of the coins deposited. In other words, they analyze the density of the coins. United States coinage is minted within very narrow specifications, so the density of each type of coin is always the same. The coin detectors compare the coins inserted to the preset standards to determine if the correct combination of coins has been deposited. In this lesson, you too will determine the density of various coins. OBJECTIVES Recognize the characteristics of density. Design and carry out a scientific investigation. Present your findings in a scientific report. Online Lab This animation will allow you to find the density of a penny, a nickel, and a quarter. Make a hypothesis in which you suggest which coin will have the highest density and which will have the lowest density. A model hypothesis might be: "If the (fill in the name of a coin) has a greater density than the _____ and _____, then it will have a greater mass to volume ratio. If the (fill in the name of a coin) has a lower density than the _____ and _____, then it will have a lower mass to volume ratio. Remember to record your data and observations in the data sheet so that you can use them to present your findings. SHOW TRANSCRIPT Present Your Findings Write a one or two summary paragraph discussing this experiment and the results. Use the following questions and topics to help guide the content of your paragraph. According to your data, was your hypothesis correct? (Be sure to refer to your data when answering this question.) Summarize any difficulties or problems you had in performing the experiment that might have affected the results. Describe how you might change the procedure to avoid these problems. List at least two real world examples that apply the findings of this experiment. (Hint: An example of this type was given in the introduction to this project.) What would you like to do next?
Answer:
If the Quarter has a greater density than the nickel and penny, then it will have a greater mass to volume ratio.
Explanation:
sorry thats all i can help with!
Why do the positive charges in the sugar grain not move?
1. Because protons are "stuck" in the nucleus, so they don't move between atoms in a material
2.
Because they are attracted by the negative tupperware
3. Because they are repelled by the negative tupperware
4.
Because the positive charges feel no attractive force from the tupperware
A box is suspended from a crane at a height of 32 m from the ground. The box has 7840 j of gravitational potential energy. What is the mass of the box
Answer:
The mass of the box is 24.97 [kg]
Explanation:
In order to solve this problem, we must use the concept of potential energy, which is defined as the product of mass by gravity by height. So we have the following equation.
[tex]E_{p} =m*g*h[/tex]
where:
Ep = potential energy [J]
m = mass [kg]
g = gravity acceleration = 9.81 [m/s^2]
h = elevation = 32 [m]
7840 = m*9.81*32
m = 24.97 [kg]
How does the approximate number of atoms
in the air in your lungs compare to the num-
ber of breaths of air in the atmosphere of the
whole world?
I don’t understand what this is asking...
You have a bowling ball with a mass of 4kg. You throw it with an acceleration of 10 m/s/s. With how much force will it hit the pins?
Answer:
The answer is 40 NExplanation:
The force acting on an object can be found by using the formula
force = mass × accelerationFrom the question
mass = 4 kg
acceleration = 10 m/s²
So we have
force = 4 × 10
We have the final answer as
40 NHope this helps you
Find kinetic energy if that same mass is now moving at a velocity of 3 m/s
Answer:
what is the mass???
Explanation:
just take the mass(kg) and half it
then take the halved mass and multiply it by 3 m/s
What speed should a spaceship of mass 5.21 x 107kg moving around a planet
only by the gravitational force be, if the distance between them is 6.27 x 108 m
and the mass of the planet is 4.76 x 1026 kg? Estimate G as 6.67 * 10-11 N (m/kg)
A. 7.12 x 103 m/s
B. 6.23 x 103 m/s
С. 4.25 x 103 m/s
D. 7.43 105 m/s
E. 7.25 x 103 m/s
Answer: A
Explanation:
The speed of the spaceship moving around a planet only by the gravitational force is 7.12 × 10³ m/s.
What is centrifugal force?A fictitious force that moves in a circle and is directed away from the center of the circle is called centrifugal force. When measurements are taken in an inertial frame of reference, the force does not exist. It only becomes relevant when we switch from a ground/inertial reference frame to a rotating reference frame.
The centrifugal force's unit is newton.
As the gravitational force is balanced by centrifugal force is orbital motion:
Gravitational force =centrifugal force
GMm/r² = mv²/r
v² = GM/r
v = √( GM/r)
= √(6.67×10⁻¹¹ ×4.76 ×10²⁶/6.27 ×10⁸)
= 7.12 × 10³ m/s.
Hence, The speed of the spaceship is 7.12 × 10³ m/s. Hence, option (A) is correct.
Learn more about centrifugal force here:
https://brainly.com/question/17167298
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what will be the resistivity of a metal wire of 2m length and 0.6mm in a diameter ,if the resistance of the wire is 50ohm . find the resistance of the same wire of 2m length and 0.3mm thickness
Answer:Resistivity of the wire is 7.065 × 10^-8 Ω m.
Explanation:
I have no idea i just googled it
Noble Gases do not readily form compounds because they ___ chemically stable with 8 valence electrons
Answer : Noble Gases do not readily form compounds because they are chemically stable with 8 valence electrons.
Explanation :
Noble gases are the chemical elements that are present in group 18 in the periodic table.
The elements are helium, neon, argon, krypton, xenon and radon.
They are chemically most stable except helium due to having the maximum number of 8 valence electrons can hold their outermost shell that means they have a complete octet.
They are rarely reacts with other elements to form compounds by gaining or losing electrons since they are already chemically stable.
Hence, the noble Gases do not readily form compounds because they are chemically stable with 8 valence electrons.
How can a person’s movement away and towards a reference point be analyzed using a position-time graph?
Answer:
Explanation:
You can plot their change in position per unit of time. By taking the slope of this graph, you can figure out the velocity at any point
Diamonds have a score of 10 on the Mohs scale. Therefore, they are used in grinding belts to buff and smooth other materials. What physical property is demonstrated by this? brainly
Answer:
Hardness
Explanation:
It has a score of 10 on the Mohs scale of HARDNESS
A doctor pushes the plunger of syringe down and then pulls it up to a draw liquid into a syringe? give reason please help me with very short answer
Answer:
When the doctor has the syringe, it is full of air. So, now after the doctor pushes the plunger, hence the air gets released into the medicine container. After this the doctor then takes the plunger and pull it back. Now , the air gets pulled up back into the syringe, but not only does the air come in but also the medicine because of the pressure build up.
If my answer helped, please mark me as the brainliest!!
Thank You!
How is mercury obtained and separated from other nearby substances?
An airplane flying due north at 90km/h is being blown due west at 50 km/h. What is the magnitude of the resultant velocity of the plane?
Answer: 103 km/hr
Explanation:
Guessed on ck-12 and it ended up being right.
Answer:
50
Explanation:
He/she guessed...Ig its 50.
Question: Carbon Dioxide is a serious danger because if causes...?
Answer:
Symptoms of carbon dioxide toxicity include high blood pressure, flushed skin, headache and twitching muscles
Hope this helps :)
9. What force is felt on a person when they 'free-fall down a large roller
coaster hill?
A thin plastic rod of length 2.5 m is rubbed all over with wool, and acquires a charge of 75 nC, distributed uniformly over its surface. Calculate the magnitude of the electric field due to the rod at a location 7 cm from the midpoint of the rod. Do the calculation two ways, first using the exact formula for a rod of any length, and second using the approximate formula for a long rod.
Answer:
find out the le
Explanation:
Use this graph to answer.
Calculate the turtle’s velocity during the following time intervals: 0-2
Answer:
10 m/s
Explanation:
Find the displacement.
xf - xi = d
0 - (-10) = 10 m
Find the acceleration.
d = 1/2at^2
10 = 1/2a(2)^2
10 = 1/2a(4)
10 = 2a
a = 5 m/s^2
Find the velocity.
v = at
v = 5(2)
v = 10 m/s
Hillary is dropping objects that are the same volume. She wants to investigate how an object’s mass affects the average speed at which it travels when dropped, until it hits the ground. Which variable must Hillary change during the experiment?
A. the timer
B. the drop height
C. the mass of the object
D. the place where she drops it
Answer:
letter C. The mass of the object.
Explanation:
i hope it helps.
A parachute on a racing dragster opens and changes the speed of the car from 79.33 m/sec to 41.55 m/sec in a period of 5.21 seconds. What is the acceleration of the dragster?
Answer:
c: -7.25
Explanation:
Here we can use the equation v=u+at
Where v is the final velocity
u is the initial velocity
a is acceleration
and t is time
41.55=79.33+a(5.21)
41.55-79.33=5.21a
-37.78=5.21a
a=-7.25 m/[tex]s^2[/tex]
The negative sign is due to the fact that they are slowing down
Neglecting air resistance, if you throw a ball straight up with a speed of 20 m/s how fast will it be moving when you catch it
Find the mass of an object on earth that weighs 39 N?
Answer:
3.9kg
Explanation:
From newton's second law of motion
F =ma
a = 10m/s^2
F=39N
a= F/m
a= 39/10
a= 3.9m/s^2
DESPERATE WILL GIVE BRAINLIST
How long does it usually take for a rock to undergo a stage within the rock cycle?
A. a few days
B. from 300 to 400 years
C. about one thousand years
D. thousands to millions of years
Answer: D. thousands to millions of years
Explanation: Stages within a rock's cycle cannot happen quickly. The formation and deterioration can take thousands to millions of years to occur.
I hope this helps!
Good luck <3
Tim was recently released from his last job. He was very rigid and would not change a product design once he began a project. He is now working for a new engineering firm and has learned from his last mistake. He is willing to meet with clients to change the needs of each and every situation. As a result, his work is now .
Answer:
Flexible and responsive to the clients requests
Explanation:
Change in design is the alteration of the specification of a product based on present or current requirements, as such change in design can take place at any stage of a product life cycle.
However, it is more cost effective to make changes to the design at the early stages of a product than at the later stages, due to the cost incurred in making adjustments and the previous expenses incurred if the design that was later changed had moved into more advanced stages.
A rock falls from rest off a high cliff. How far has the rock fallen when its speed is 39.2 meters per second?
( plss I need help lol)
The rock fell as far as 78.4 meters.
Given the following data:
Initial speed = 0 m/s (since the rock fell from rest). Final speed = 39.2 m/sWe know that the acceleration due to gravity (a) for an object is equal to 9.8 meter per seconds square.
To find how far (distance) has the rock fallen, we would use the third equation of motion;
[tex]V^2 = U^2 + 2aS[/tex]
Where:
V is the final speed. U is the initial speed. a is the acceleration. S is the distance covered.Substituting the given parameters into the formula, we have;
[tex]39.2^2 = 0^2 + 2(9.8)S\\\\1536.64 = 0 + 19.6S\\\\19.6S = 1536.64\\\\S = \frac{1536.64}{19.6}[/tex]
Distance, S = 78.4 meters.
Therefore, the rock fell as far as 78.4 meters.
Read more: https://brainly.com/question/8898885
If the mass of one object is doubled and mass of other remains the same and if distance between them is halved then how does the gravitational force change?
Does change in direction affect the acceleration of a car?
Answer:
A change in velocity is either a change in an object's speed or its direction. When a moving object changes direction, its velocity changes and it is accelerating.
Explanation:
You are at the Super Bowl. The coach puts you in during the 4th quarter to be the quarterback to secure your team the win. Since you are fresh off the bench, you are able to throw the ball with more force than the last person. What advantages, using Newton's second law, will this have when playing?
Answer:
the ball will fly faster, and longer distance, which means there is going to be less air resistnace friction acting upon the ball.
Explanation:
An automobile traveling along a straight road
increases its speed from 53 ft/s to 68 ft/s in
180 ft.
If the acceleration is constant. how much
time elapses while the auto moves the 180 ft?
Answer in units of s.
Answer:
t = 2.97[s]
Explanation:
To solve this problem we must use the following kinematics equations, we must bear in mind that the positive sign of the acceleration value means that the car is increased its speed.
[tex]v_{f}^{2} =v_{o}^{2} +(2*a*(x-x_{o} ))[/tex]
where:
x - xo = 180 [ft]
a = acceleration [ft/s^2]
Vo = initial velocity = 53 [ft/s]
Vf = final velocity = 68 [ft/s]
Now replacing we find:
(68^2) = (53^2) + (2*a*180)
a = 5.04 [ft/s^2]
Now using the following equation:
[tex]v_{f}=v_{0}+a*t[/tex]
68 = 53 + (5.04*t)
t = (68 - 53)/5.04
t = 2.97[s]