A student is standing on a very steep hill, kicks a soccer ball horizontally with a speed of 10 m/s toward a student who is sitting on a level field 3 meters below. How long does it take the soccer ball to strike the ground?
Answers
Answer:
0.782 seconds
Explanation:
We are given that the ball starts out on a hill that is 3 m above a level field below. And that the ball is kicked horizontally. We are asked how long the ball takes to hit the ground 3 meters below.
On closer consideration of the given situation, it is important to realize that even though the ball starts out with a speed of 10m/s in the horizontal direction, that this will not make a difference in how fast the ball travels in the vertical direction (which is what the question is basically asking for). Hence for this question, we can ignore the initial horizontal speed of the ball and realize that the initial vertical speed is 0 m/s.
Recall that one of the equations of motion can be expressed as:
s = ut + (1/2) at² (refer to attached for reference)
where,
Applied in the vertical direction,
s = vertical distance travelled = 3 meters in this case
u = initial vertical velocity = 0 m/s in this case
a = acceleration due to gravity, g = 9.81 m/s²
t = time taken ( we are asked to find this)
simply substituting the known values above into the equation:
s = ut + (1/2) at²
3 = 0 + (1/2) (9.81)t²
3 = 4.905t²
t² = 3 / 4.905
t² = 0.61162
t = √0.61162
t = 0.782 seconds
Related Questions
look at the photo thank you
Answers
Answer: The ballon could get rub on a carpet to gain electricity and it would have enoght force
Explanation:
A car starts at rest and accelerates at a constant rate for 12 seconds to speed of 30 m/s. What is the total distance traveled in these 12 seconds
Answers
Answer:
360 meters
Explanation:
1. Set up a formula. Distance = Speed x Time
2. Plug in given information. d (distance) = 30m/s * 12s
3. Multiply numbers AND units. d = 360m
4. Check that units & numbers make sense.
Speed is a measure of how quickly an object moves.
The speed equation can be rearranged to calculate the distance traveled and the time required.
The total distance traveled in these 12 seconds = 360 m.
What is speed ?Speed is a measure of how quickly an object moves. Use the speed equation to calculate speed: speed = distance divided by time. The speed equation can be rearranged to calculate the distance traveled and the time required.Speed is the rate at which an object moves along a path in time, whereas velocity is the rate and direction of movement. In other words, velocity is a vector, whereas speed is a scalar value.The force of impact increases with the square of the increase in speed, according to physical laws. So, doubling the speed of a car increases the force of impact fourfold.The total distance traveled in these 12 seconds = 30 m/s x12 sec
=360 m.
To learn more about : Speed
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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?
Answers
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!
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?
Answers
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:
Force = mass x acceleration
Mass of football remains constant, fresh arm of QB provides higher acceleration.
Ball will get to receiver faster.
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?
Answers
New force = 8 x original force
How do you find the total number of nodes in a two-source interference pattern?
I know the formula is like Na=d/lambda but apparently, according to my physics teacher, you have to go one step further to find the total number of nodes. But he never showed us how, and I cant find anything online.
Like for example if the distance between the two sources was 20cm and the wavelength was 2cm, then it would be 20/2=10 right? But my teacher said its wrong. And he wont explain why.
I have a test on this tomorrow please help
Answers
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.
Answers
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]
1.a car sitting at rest on the road
balanced or unbalanced
explain your answer
Answers
Answer:
Balanced force
Explanation:
Balanced Forces, When forces are in balance, acceleration is zero. Velocity is constant and there is no net or unbalanced force. ... Although friction is acting on the person, there is no change in velocity and friction is not a net force in this case. Friction is only a net force if it changes the velocity of a mass.
The car is balanced.
If there are any forced acting on it, then those are balanced too.
How much kinetic energy does a baseball with a mass of 0.143 kg have it it is traveling at a velocity of 41.1 m/s?
89.7 Joules
108 3 Joules
156.6 Joules
120.8 Joules
Answers
Answer:
E = 120.77 J
Explanation:
Given that,
Mass of a baseball, m = 0.143 kg
Velocity of a baseball, v = 41.1 m/s
We need to find the kinetic energy of the baseball. We know that the kinetic energy of an object is associated with its motion. It can be given by the formula as follow :
[tex]E=\dfrac{1}{2}mv^2\\\\E=\dfrac{1}{2}\times 0.143\ kg\times (41.1\ m/s)^2\\E=120.77\ J[/tex]
So, the kinetic energy of the baseball is 120.77 J.
The kinetic energy of the baseball is 120.8 J.
What is kinetic energy?The kinetic energy of an object is associated with its motion. It can be related to the mass and velocity as
K.E = 1/2 mv²
Given is the Mass of a baseball, m = 0.143 kg and Velocity of a baseball, v = 41.1 m/s
substitute the values, we have
K.E = 1/2 x 0.143 x (41.1)²
K.E = 120.77 J
Hence, the kinetic energy of the baseball is 120.8 J.
Learn more about kinetic energy.
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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 .
Answers
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 balloonist drops his camera from a height of 100 m while his balloon is ascending at 5 m/s. How
long did it take to reach the ground?
Answers
A tennis ball is dropped from 1.3 m above
the ground. It rebounds to a height of
0.943 m.
With what velocity does it hit the ground?
The acceleration of gravity is 9.8 m/s². (Let
down be negative.
Answer in units of m/s.
part 2 of 3
Answers
Answer:
2.65m/s
Explanation:
Using the equation of motion:
v² = u²+2a∆S where
v is the final velocity
u is the initial velocity
∆S is the change in distance
a is the acceleration
Given
u = 0m/s
a = 9.8m/s²
∆S = 1.3-0.943
∆S = 0.357m
Substituting the given parameters into the formula
v² = 0²+2(9.8)(0.357)
v² = 0+6.9972
v² = 6.9972
v=√6.9972
v = 2.65m/s
Hence the velocity at which it hit the ground is 2.65m/s
why light waves are called electromagnetic waves ?
Answers
Does change in direction affect the acceleration of a car?
Answers
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:
Atoms are known to form charges due to their ability to gain and lose electrons in reactions. As a result, atoms
become ions that are positively or negatively charged depending on the loss or gain of electrons. Which of the
following atoms has a charge of +2 given the number of electrons?
O A. O: 10 electrons
OB. N: 10 electrons
O C. Fe: 24 electrons
OD. Cl: 18 electrons
Answers
Answer:
C. Fe: 24 electrons
Explanation:
From the analogy given, the atom with a charge of +2 is Fe having 24 electrons.
To calculate the charges on an atom;
Number of charges = Number of protons - Number of electrons.
O: 10 electrons: 8 protons = 8 - 10 = -2
N: 10 electrons; 7 protons = 7 - 10 = -3
Cl: 18 electrons; 17 protons = 17 - 18 = -1
So;
Fe: 24 electrons and 26 protons = 26 -24 = +2
Therefore, the solution is Fe
When you travel 20km in 1 hour, at what speed do you travel.
Answers
Answer:
at 20km/h
Explanation:
9. What force is felt on a person when they 'free-fall down a large roller
coaster hill?
Answers
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...
Answers
Find the volume of a sphere of radius 6020000 m and subtract the volume of the Earth which is a sphere of radius 6000000 m (approx).
This would be the volume of air in m^3.
Approximate the lungs as a cube, it would be approx 0.2m x 0.2m x 0.2 m = 0.008 m^3
Divide the volume of air around the Earth by 0.008.
0.001 m^3 of air contains about 6 x 10^23 molecules which is about 12 x 10^23 atoms.
If your lungs are 0.008 m^3 then that would be about 96 x 10 ^23 or about 10^25 atoms.
Compare that number with the earlier number when dividing air in the atmosphere by 0.008.
I hope this helps. :)
Noble Gases do not readily form compounds because they ___ chemically stable with 8 valence electrons
Answers
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.
True or False : the collect of evidence fall onto the detectives that arrive at a crime scene
Answers
Answer:true
Explanation:
why are those who take bribery or give bribery considered enemies of the nation?
Answers
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
Answers
Answer:Resistivity of the wire is 7.065 × 10^-8 Ω m.
Explanation:
I have no idea i just googled it
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?
Answers
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
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.
Answers
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
Light waves pass through two openings and interfere, producing light and dark areas. Which of the following statements is true with regard to the areas that are produced?
A.The bright areas are produced by the destructive refraction of light waves.
B.The dark areas are produced by the destructive refraction of light waves.
C.The dark areas are produced by the constructive interference of light waves.
D.The bright areas are produced by the constructive interferences of light waves.
Answers
A car travels from 20-meters to 60-meters in 10 seconds. Calculate the car's speed.
Answers
Answer:
8 m/s
Explanation:
All you have to do here is add 20 and 60 (giving you 80) and dividing by 10 seconds. 80/10= 8 m/s
Question: Carbon Dioxide is a serious danger because if causes...?
Answers
Answer:
Symptoms of carbon dioxide toxicity include high blood pressure, flushed skin, headache and twitching muscles
Hope this helps :)
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
Answers
Answer:
letter C. The mass of the object.
Explanation:
i hope it helps.
Why is the law of gravity an example of a universal law?
A. Gravity exists between small masses in an open system only.
B. Gravity exists between any two masses.
C. Gravity exists only on the earth and the moon.
D. Gravity exists for masses in a closed system only.
Answers
Answer:
B
Explanation:
i took the test
in a series circuit, why is the current always the same?
Answers
Answer:
here lol
Explanation: