Answer:
1) The angle of projection of the ball is approximately 52.496° above the horizontal
2) The velocity with which the boy throws the ball to enable him accomplish his desire is approximately 14.769 m/s
Explanation:
In the projectile motion of the ball, the parameters are;
The distance the boy stands from the front of the house = 5 m
The depth of the house, front to back = 6 m
The height of the opening of the front window above him = 5 m
The height of the back window = 2 m higher than the front window
Therefore, the height of the back window = 5 m + 2 m = 7 m
1) The general formula for the vertical height of a parabolic projectile motion is given as follows;
y = a·x² + b·x + c
At y = 0, x = 0, therefore, c = 0
At y = 5, x = 5, we have;
5 = a·5² + b·5
∴ 5 = 25·a + 5·b...(1)
At y = 7, x = 11, we have;
7 = a·11² + b·11
7 = 121·a + 11·b...(2)
Making 'a' the subject of equation (1) and (2) and equating both values of 'a' gives;
For equation (1);
a = (5 - 5·b)/25 = 1/5 - b/5
a = 1/5 - b/5
For equation (2);
a = (7 - 11·b)/121 = 7/121 - b/11
a = 7/121 - b/11
∴ 1/5 - b/5 = 7/121 - b/11
1/5 - 7/121 = b/5 - b/11
86/605 = 6·b/55
b = (86/605) × (55/6) = 43/33
b = 43/33
a = 1/5 - b/5 = 1/5 - (43/33)/5 = -2/33
∴ y = (-2/33)·x² + (43/33)·x
The slope of the curve = dy/dx = d((-2/33)·x² + (43/33)·x)/dx = -4/33·x + 43/33
The slope of the curve at any point on the projectile = -4/33·x + 43/33
The slope at the origin is given by plugging x = 0 as follows
The slope at the origin = -4/33 × 0 + 43/33 = 43/33
The slope at the origin = tan(θ) = 43/33
Where;
θ = The angle of projection of the ball
∴ θ = arctan(43/33) ≈ 52.496°
The angle of projection of the ball, θ ≈ 52.496° above the horizontal
2) At the back widow, the equation for the vertical height, 'h', is given as follows;
[tex]h = (tan \angle \theta) \cdot x - \left(\dfrac{g}{2 \cdot v_1^2 \cdot cos^2 \angle \theta } \right )\cdot x^2[/tex]
Where;
h = The vertical height of the back window = 7 m
tan∠θ = 43/33
x = The horizontal distance of the back window from the boy = 5 m + 6 m = 11 m
g = The acceleration due to gravity = 9.8 m/s²
v₁ = The velocity with which the boy throws the ball
cos²∠θ = cos²(arctan(43/33)) = 1089/2938
Plugging in the values gives;
[tex]7 = \left (\dfrac{43}{33} \right) \times 11 - \left(\dfrac{9.8}{2 \cdot v_1^2 \cdot \dfrac{1089}{2938} } \right )\cdot 11^2[/tex]
[tex]\therefore v_1^2 = \dfrac{71981}{330}[/tex]
[tex]\therefore v_1 = \sqrt{\dfrac{71981}{330}} \approx \pm14.769[/tex]
The velocity with which the boy throws the ball to enable him accomplish his desire, v₁ ≈ 14.769 m/s.
A kid is bouncing on a pogo stick. He oscillates 22.0 times in 14.9 S. What is his frequency? (Unit = Hz)
Answer:
1.4765 Hz
Explanation:
right on acellus
The frequency of an event is the inverse of time period.The frequency of the kid on bouncing the pogo stick is 1.47 Hz.
What is frequency?Frequency of an event is is the number of occurance of that event in unit time. It is the inverse of time period of that event. Hence frequency has the unit of s⁻¹ which is equivalent to Hz.
The frequency of a wave is the number of wave cycles per unit time. Frequency is directly related to the energy of the vibration or wave. Hence, as the frequency increases, energy increases.
Given that, the number of oscillations from the bouncing of the pogo stick is 22 times in 14.9 seconds. Thus , number of oscillations in 1 second is:
22 /14.9 s = 1.47 Hz.
Therefore, the frequency of the event created by the kid is 1.47 Hz.
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what are the methods of avoiding demagnetization
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The best method to use in prevention of self-demagnetization of a permanent magnet is by use of a keeper. Keepers were also commonly known as amateurs. They help in storing magnets safely, especially those that have low coercivity ( magnets that are extremely susceptible to stray fields).
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Hope It Helps!
a bicyclist travels with an average velocity of 15 km per hour for 20 minutes what is his displacement in kilometer
Answer:
5 kilometers
Explanation:
Velocity= 15km/h
Time= 20 minutes = 1/3 hours
Displacement= Velocity x Time
= 15 x 1/3
= 15/3
= 5km
Can you freeze sound waves
Answer:
I believe it's not possible
Explanation:
there's really no way I currently know of that we can do that so I suppose no.
which of the following instrument measure time most accurately
Answer:
What are the options???
Answer:
Electronic stopwatch
Explanation:
lectronic stopwatch, stop clock, pendulum clock and hour glass are the instruments used for measuring the time. Among the following, electronic stopwatch has the highest level of accuracy whereas hourglass has the lowest level of accuracy in measuring time.
Can a physical quantity have units but still be dimensionless?
Answer:
yes
Explanation:
there are other quantities that are dimensionless, but have a unit.
For example, radian is the unit for an angle. But it is dimensionless because it is defined to be the ratio of two lengths.,
a dimensionless quantity will always be independent of the base units — meter, second, kilograms, kelvin, candela, moles, ampere.
Other examples:
1. Mass fraction
2.Mole fraction
both have unit (kg/kg)
Answer:
A quantity that has dimensions must have units. Yes a quantity have units but still be dimensionless for example,unit of angle is radian ,but it is a dimensionless quantity. A dimensionless quantity may have unit. ... A unitless quantity never has a non-zero dimension.
I hope it's helpful!
I WILL GIVE BRAINLIST TO CORRECT ANSWERSSSS
Examine the symbols below:
Four schematics are shown. Each symbol shows a cell schematic with the plus and minus symbols. Symbol A has the pattern: long, short, long, and short lines. Symbol B has the pattern: long, short, long, short, long, and short lines. Symbol C has the pattern: long and short lines. Symbol D has the pattern: long, short, long, and short but rotated horizontally.
Which image represents a three-battery cell in a circuit? (2 points)
Group of answer choices
Symbol A
Symbol B
Symbol C
Symbol D
Answer:
The answer is SYMBOL B.
Explanation:
The correct schematic is the one that shows three groups of long and short lines. A schematic with one long and one short (one group) would be a one cell; a schematic with a long, a short, a long, a short (two group), would be a two cell; and a schematic with a long, a short, a long, a short, a long and a short (three group), would be a three cell- hence why the answer is symbol B.
Answer:
Symbol B
Explanation:
I took the test :)
what are the different benefit of walking?
Answer:
U can walk to the bathroom
Explanation:
Lowest form of energy from the sun
UVA
I'm pretty sure it's UVA :)
things plants make during photosynthesis
Answer:
glucose
Explanation:
convert starch to glucose
Answer:
During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. These sugar molecules are the basis for more complex molecules made by the photosynthetic cell, such as glucose.
I hope it's helpful!
plzs help me asap!!!!!
Directions: Write a T in the blank for True, or an F for False.
6. Newton's First Law states that every action has an equal/opposite reaction.
7. Newton's Second Law can be simplified to F=ma.
8. An object will move in the same direction as the unbalanced force acting upon it.
9. Friction always acts in the same direction as the motion of the object.
10. If there is no next force acting on an object, that means in ALL SITUATIONS that the object will not move.
Answer:
6. False 7. True 8. False (Unbalanced forces acting upon an object changes the object's motion) 9. False 10. True (I'm not 100% sure if these answers are right though.)
Answer:
I confirm that answer LOL
Explanation:
An object that is not moving has no energy?
Answer: A motionless object can have energy. The energy that the object has is called potential energy.
Explanation:
IF you are in Space and push a bowling what happens to you and the bowling ball?
Answer:
The bowling ball did not change size or shape- the only thing that changed was the amount of gravity that pulls on it. But the mass of the bowling ball would never change. A bowling ball with a mass of 12 pounds on earth will have the mass of 12 pounds on the moon! Mass is the amount of atoms that a space fills.
Explanation:
I hope this helps! :D
How can you increase the current in a circuit?
I. Decrease the potential difference
II. Increase the potential difference
III. Decrease the resistance
Answer:
By decreasing the resistance
ANSWER QUICK PLEASE!!! (WORTH 15 POINTS!)
Kellie is hopping on one foot. Kellie has a mass of 650
newtons and her foot has an area of 0.10 m2.
How much pressure is exerted by her foot on the ground
with each hop?
Answer:
650 N / 0.10 m2 = 6500 Pa
Explanation:
The pressure that could be exerted on the ground with each top should be 6,500 Pa
Given that,
The mass is 650 newtons.The area should be 0.10m^2We need to determine the pressure.
So, the following formula should be used.
[tex]= \frac{Mass}{area}\\\\= \frac{650}{0.10} \\\\[/tex]
= 6,500 Pa
Therefore we can conclude that the pressure that could be exerted on the ground with each top should be 6,500 Pa.
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1. Pressing force = 10N , Area= 2m2 : Calculate pressure in N/m2
2. Pressing force = 70N, Area = 0.2m2 : Calculate pressure in N/m²
3. Pressing force = 300N , Area = 0.01m?: Calculate pressure N/m
4. Pressing force = 500N, Pressure = 20N/m² : Calculate area in m
5. Area = 0.003m2, Pressure = 15000N/m2 : Calculate the pressing force in N
I am so confused
if the battery is a 9-volt battery and the resistance in the circuit is 18 ohm's how much current is flowing through the circuit
Answer:
0.50 A
Explanation:
According to the formula, V = IR
9 = I×18
I = 9/18
I = 0.50
If the battery is a 9-volt battery and the resistance in the circuit is 18 ohm's then the current is flowing through the circuit would be 0.5 Ampere.
Resistance is the obstruction of electrons in an electrically conducting material.The mathematical relation for resistance can be understood with the help of the empirical relation provided by Ohm's law.
V=IR
Where V is the voltage
Where I is the current
Where R is the resistance used in the circuit
As for the given problem if the battery is a 9-volt battery and the resistance in the circuit is 18 ohm
By using the ohms
V=IR
By substituting the respective value of voltage and resistance
Voltage is 9 volt in the resistance is 18 ohm
9V = 18*I
I= 0.5 Ampere
Thus, the current flowing through the 9 V battery and a 18 Ohm resistor is 0.5 Ampere.
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The body weighing 8kg moves in a straight line uniformly accelerated with an acceleration of 3m / s? on a horizontal surface, under the action of force 60N.Find a) What is the friction force acting on the body) The coefficient of friction between the body and the surface where it moves
Answer:
the friction force f=36
and the coefficient of friction =0.45
need physics help
ASAP please!
Answer:
D
Explanation:
what is the dimensional formula of thermal conductivity?
Answer:
The dimension of thermal conductivity is M1L1T−3Θ−1, expressed in terms of the dimensions mass (M), length (L), time (T), and temperature (Θ). Other units which are closely related to the thermal conductivity are in common use in the construction and textile industries.
Explanation:looked it up for ya
Anyone knows this? Please answer... Spam will be reported.
Answer:
The correct option is;
The assertion is correct, but reason wrong
Explanation:
The question is with regards to the relationship between work, energy, power, and velocity
The mass of each of the persons running up the staircase = Different
The time it takes each person to run up the stairs = Equal time
Let, 'm₁' and 'm₂' represent the mass of each of the persons that ran up the stairs and m₁ > m₂
Let 't' represent the equal time it takes then to run up the stairs
Let 'h' represent the height of the stairs
The energy, 'E', it takes to run up the stairs is equal to the potential energy, P.E., obtained at the top of the stairs
P.E. = m·g·h
Where;
m = The mass of the person at an elevated height
g = The acceleration due to gravity = Constant
h = The height reached above ground level
Given that the height reached is the same for both of the persons, we have
For m₁, P.E.₁ = m₁·g·h and for m₂, P.E.₂ = m₂·g·h
Therefore, where, m₁ > m₂, we have;
P.E.₁ > P.E.₂
∴ E₁ > E₂
Power, 'P', is the rate at which energy is expended
∴ Power, P = E/t
∴ P₁ = E₁/t > P₂ = E₂/t
Therefore, the person with the greater mass, 'm₁', uses more power than the person of mass 'm₂', in running up the stairs
Therefore, the assertion is correct
The average velocity, vₐ = (Total distance traveled, d)/(Total time taken, t)
Given that the distance, 'd', covered in running up the stairs by both persons is the same, and the time it takes them to complete the distance, 't', is also the same, we have;
The average velocity of the person with the greater mass m₁ is the same as the average velocity of the person with mass, m₂
Therefore, the reason is wrong
The answer is that the assertion is correct, but reason wrong
Question 8
Brooke wakes up in the morning to find a rainbow produced by light shining through the fish tank near
her window. Which of the following types of electromagnetic radiation produced the rainbow that
Brooke saw?
Ultraviolet
Infrared
White light
Gamma rays
Answer:
3.white light
If the speed of sound in air is 340 m/s, approximately how long will it take the sound of a clap of thunder to travel 2 kilometers?(1 point)
5.9 seconds
3.4 seconds
2.9 seconds
1.7 seconds
Answer:5.9 Seconds
Explanation: I just took the quiz
The sound of a clap of thunder take 5.9 seconds to travel 2 kilometers.
To determine the correct statement among all the options, we need to know about the relation between speed and time.
What is sound speed?The speed of sound is the distance travelled by sound per unit time Mathematically, it is v=distance/time= 340m/s.What's is the time taken by sound to travel 2 km?We found 340m/s=distance/time. So, time = distance/340= 2000m/340= 5.9 s.Thus, we can conclude that the sound of a clap of thunder take 5.9 seconds to travel 2 kilometers.
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Which one of the following best describes a fuse?
Page No.:
Date :
*
What is the physical meaning of emissivity write its unit
Answer: a measure of the ability of a surface to radiate energy; the ratio of the radiant flux emitted per unit area to that emitted by a black body at the same temperature.
Explanation: hope that helped! (:
are brought close together?
5. What happens when like magnetic poles
Answer:
When two magnets are brought together, the opposite poles will attract one another, but the like poles will repel one another. This is similar to electric charges. Like charges repel, and unlike charges attract.
Buoyancy All soda cans contain the same
volume of liquid, 354 mL, and displace the
same volume of water. What might be a
difference between can that sinks and one
that floats? Hint: Place a full can of regular
soda and a full can of diet soda in water.
Answer:
The correct answer is - Regular soda can would sink and diet soda can will float.
Explanation:
The correct answer is - Regular soda can would sink and diet soda can will float.
Reason - As diet soda cans contains artificial sweetener so, the weight of the diet soda can is less the the eight of the regular soda so. Due to this reason , diet soda can will float and another one sinks in water.
9. CALCULATE: How much more power is used to move a weight of 500 N a distance of 20 m in 5 s than is used to move a weight of 1,000 N a distance of 30 m in 30 sec?
Answer:
work = 500*3 = 1500 J
1500J in 5 sec = 300 watts
Explanation:
Answer:
it is using the same power
Explanation:
it is using the same power because it has to move longer and a farther distance while the other one has double the power but less the distance
Are anxiety disorder curable
Anxiety disorders are not completely curable.
What are anxiety disorders?An anxiety disorder is a disorder in which an individual easily develops feelings of anxiety even in situations which do not warrant such feeling.
The individual feels excessively anxious that it becomes a disability and does not allow the individual to live a normal life.
There are five main types of anxiety disorders and they are as follows:
Generalized Anxiety DisorderObsessive-Compulsive DisorderPanic DisorderPost-Traumatic Stress DisorderSocial Phobia or Social Anxiety DisorderAnxiety disorders are not completely curable since they are purely psychological problems.
However, therapy and psychological assistance can lessen symptoms.
In conclusion, anxiety disorders affect productivity and makes an individual excessively anxious.
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When digging a hole to plant a shrub in hard ground, is it better to use a long-handled or short-handled shovel?
Answer: long handle
Explanation: they are better for tree planting and other hole-digging. Long shovel handles can reach deep into a hole. And you'll get better leverage, which is easier on your back. ... The lighter the shovel, the easier time you will have digging.
