Answer:
The speed of the water bottle at impact with the street is 49 m/s
Explanation:
Free Fall Motion
A free-falling object falls under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. Free-falling objects do not experience air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is [tex]g = 9.8 m/s^2[/tex].
The final velocity of a free-falling object after a time t is given by:
vf=g.t
The water bottle dropped by Jamie takes t=5 seconds to impact the ground, thus its speed at that moment is:
vf= 9.8*5
vf = 49 m/s
The speed of the water bottle at impact with the street is 49 m/s
Eating 2500 Cal every day a friend of mine maintains a stable weight of 70 kg. One day, after eating 3500 Cal, he decided to do extra exercise to avoid gaining weight. He was doing jumps: he leaves the ground with a speed of 3.3m/s at every jump. Assuming that his body turns energy to mechanical work with a 25 % efficiency, how many jumps he will have to make
Answer:
2721
Explanation:
First, we find the change in calories
E = E(taken) - E(daily)
E = 3500 - 2500
E = 1000 cal
Next, we use the efficiency to find the available metabolic energy
E' = n.E, where n = efficiency
E' = 0.25 * 1000
E' = 250 cal
Converting this cal to J, we have
1 cal = 4.18 J
250 cal = 250 * 4.18 J
250 cal = 1045 kJ
Given that the final velocity is 0, we use equation of motion to find the height, h attained
u² = 2gh
h = u²/2g
h = 3.3² / 2 * 9.81
h = 10.89 / 19.62
h = 0.56 m
Potential energy, E = mgh
E = 70 * 9.8 * 0.56
E = 384 J
Total number of jumps, n =
n = 1045 / 384
n = 2721 jumps
4.5. During a snowball fight, your opponent distracts you by throwing a snowball at you with a high arc. She throws snowballs with a speed of 23.3 m/s and the first is thrown at 70.0 degrees. As you are watching the first snowball, she throws a second at a lower angle. (a) If both snowballs cover the same horizontal distance, at what angle (degrees) should the second be thrown? (b) If the second snow ball is going to hit you while your attention is still focused on the first snowball, how soon (s) after the first snowball is thrown must the second be thrown? In other words, what is the delay between the two throws that will have both arriving at the same time?
Answer:
(a) θ = 20°
(b) Time Delay = 2.84 s
Explanation:
(a)
This is the case of the projectile motion. In projectile motion, for the same launch speed, the range of a projectile is the same for the complimentary launch angles. Hence, the snowball will have the same range when launched at 70°, at an angle of:
[tex]\theta = 90^{0} - 70^{0}[/tex]
θ = 20°
(b)
The time of flight of snowball can be found by the following formula:
[tex]T = \frac{2\ u\ Sin \theta}{g}[/tex]
where,
T = Time of flight = ?
u = launch speed = 23.3 m/s
g = acceleration due to gravity = 9.81 m/s²
For θ = 70° :
[tex]T_{70} = \frac{(2)(23.3\ m/s)Sin70^{0}}{9.81\ m/s^{2}}[/tex]
T₇₀ = 4.46 s
For θ = 20° :
[tex]T_{20} = \frac{(2)(23.3\ m/s)Sin20^{0}}{9.81\ m/s^{2}}[/tex]
T₂₀ = 1.62 s
Therefore, the time delay can be calculated as follows:
[tex]Time\ Delay = T_{70} - T_{20}\\Time\ Delay = 4.46\ s - 1.62\ s\\[/tex]
Time Delay = 2.84 s
A. The angle at which the second ball should be thrown is 20°
B. The delay time between the two throws is 2.83 s
A. Determination of the angle at which the second ball should be thrown
From the question given above, we were told that:
The first ball is thrown at angle of 70°. Both balls covers the same range.From the above data, the angle at which the second ball should be thrown will be = 90 – 70 = 20°
B. How to determine the delay time between the two throws I. Determination of the time of flight at angle 70°Initial velocity (u) = 23.3 m/sAcceleration due to gravity (g) = 9.8 m/s²Angle (θ) = 70°Time of flight (T) =?T = 2uSineθ / g
T = (2 × 23.3 × Sine 70) / 9.8
T = 4.45 s
II. Determination of the time flight at angle 20°Initial velocity (u) = 23.3 m/sAcceleration due to gravity (g) = 9.8 m/s²Angle (θ) = 20°Time of flight (T) =?T = 2uSineθ / g
T = (2 × 23.3 × Sine 20) / 9.8
T = 1.62 s
III. Determination of the delay time Time of flight for 70° = 4.45 sTime of flight for 20° = 1.62 sDelay time =?Delay time = 4.45 – 1.62
Delay time = 2.83 s
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A pitcher throws a 0.143-kg baseball toward the batter so that it crosses home plate horizontally and has a speed of 42 m/s just before it makes contact with the bat. The batter then hits the ball straight back at the pitcher with a speed of 49 m/s. Assume the ball travels along the same line leaving the bat as it followed before contacting the bat. If the ball is in contact with the bat for 0.005 0 s, what is the magnitude of the average force exerted by the bat on the ball?
Answer:
200N appox
Explanation:
Step one:
Given data
mass of ball= 0.143kg
initial velocity of ball u= 42m/s
final velocity of the ball= 49m/s
time of impact= 0.005s
Step two
From the relation Ft=mΔv
we can find the average force as
F=mΔv/t
substitute
F=0.143*(49-42)/0.005
F=0.143*7/0.005
F=1.001/0.005
F=200.2
F= 200N appox
The average force is 200N
9) If, after viewing a specimen at low power, you switch to high-dry power and, after using fine focus, cannot find the specimen, what things could you do to help yourself (before asking the instructor to assist you
Answer:
See the answer below
Explanation:
The best thing one can do in this case would be to return the microscope's objective to low power and then re-center the specimen before switching back to high-dry power.
Most of the time, what makes the specimen under the microscope to be out of focus at higher objective powers after being in focus at low power is because they are not properly centered on the stage. Hence, before calling on the instructor, it would be wise to first return to low power, re-center the specimen and bring it into focus after which the high power objective can be returned to and the fine focus adjusted to bring the image back to focus.
After doing the above and the specimen still does not come into focus, then the instructor can be called upon.
A spring has an elastic constant of 8.75 x 103 N/m. What is the magnitude of the force required to stretch this spring a distance of 28.6 cm from its equilibrium position?
Given :
A spring has an elastic constant of 8.75 x 10³ N/m.
To Find :
The magnitude of the force required to stretch this spring a distance of 28.6 cm from its equilibrium position.
Solution :
We know, force required to stretch a spring of spring constant k and distance x is given by :
[tex]F = \dfrac{kx^2}{2}[/tex]
Putting all given values, we get :
[tex]F = \dfrac{8.75\times 10^3 \times 0.286^2}{2}\\\\F = 357.86\ N[/tex]
Hence, this is the required solution.
Choose all the answers that apply.
Which of the following characteristics are found in flowering plants?
1. seeds
2. cones
3. reproduction by spores
4. vascular tissue
5. fruit
Answer:
Seeds And Reproduction By Spores
Explanation:
Did on Odyssey
*} The specipe heat capacity of body depends up on
(c mass of body
b) Tempreature rises (d) Nature of body
(а
(a Heat
given
Answer:
heat given , nature of body, and temperature rise
Describe what a homogeneous electric field is, and where we find such
Answer:
no one really answers on here anymore but can u click on my profile and help me with my question
Explanation:
the answer is A homogeneous electric field has the same magnitude and direction at any place. A good example of a homogeneous field is the field between two charged metal plates. The field strength depends on the voltage U and the plate distance d.
g 2. _______The property(ies) of a thermal system is (are)(A) temperature or (B) internal energy or (C) work.
Answer:
(A) temperature
Explanation:
Given that thermal properties of a material are those properties that can be observed or felt when the heat is added to the material.
Hence, in this case, the correct answer is "Temperature."
On the other hand, the internal energy is not a thermal property but rather an extensive property that cannot be assessed directly.
Also, work is not a thermal property but rather a process quantity.
A satellite is launched to orbit the Earth at an altitude of 2.25*107 m for use in the Global Positioning System (GPS). Take the mass of the Earth to be 5.97*1024 kg and its radius 6.38*106 m.
What is the orbital period of this GPS satellite?
Answer:orbital period of this GPS satellite, T= 48,874.4 s
Explanation:
Altitude (h)= 2.25 X 10^7 m
Radius of the Earth ( r)=6.38 X 10^6 m
The distance from center of the Earth to the point is given as
R = r +h
6.38 x 10^6 m+ 2.25 x 10^7 m
=28,880,000=2.888 x 10^7m
Also, Mass of the Earth =5.97 x 10^24 kg
and Gravitational Universal Constant
= 6.67 x 10^-11N.m2/kg2
Orbital period T
= 2π
=2 X 3.142[tex]\sqrt{ (2.888 x 10^7m)^3 /6.67 x 10^-11N.m2/kg2 X 5.97 x 10^24 kg}[/tex]
2X 3.142 [tex]\sqrt{60,491088.9}[/tex]
= 2X 3.142 X 7,777.60
T= 48,874.4 s
NEED HELP ASAP!!!!
A car drives around a racetrack for 30 seconds. What do you need to know to
calculate the average velocity of the car?
O A. The slope of the car's velocity-time graph
O B. The total displacement of the car
O C. The area under the position-time graph
O D. The slope of the car's position-time graph
A car drives around a racetrack for 30 seconds. To calculate the average velocity of the car we need to know about distance. from option B and D we can calculate velocity. Therefore option B and D is correct.
What is velocity ?Velocity is "rate of change of displacement with respect to time".
i.e. v= dx/dt. it is also defined as displacement over time.
i.e. v=Displacement/Time. Velocity shows how much distance can be covered in unit time. It's SI unit m/s. Dimension of velocity is [M⁰ L¹ T⁻¹].
Option A) The slope of the car's velocity-time graph.
it gives Velocity/time. we can not find average velocity with this data.
Option B) The total displacement of the car.
when we know displacement and time, we can calculate velocity. therefore this option is correct.
Option C) The area under the position-time graph.
This gives position×time, which is useless to find velocity.
Option D) The slope of the car's position-time graph.
this gives velocity of the car. Therefore this option is correct.
Hence option B and D is correct, we can calculate average velocity from them.
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The charges on the proton and electron are typically measured in: Select the correct answer below: volts amperes coulombs daltons
Answer: columbs
Explanation:
Electrical charge are measured in columbs, usually demoted as C. Hence, the charges on proton and electron will be measured in Coloumbs. It typically measures the amount of electricity conveyed per second by a current of 1 ampere. The other units Given such as ; Volt is used for measuring voltage, which is the pressure in an electrical source. AMPERE is used for measuring the current flowing through an electrical circuit.
Dalton is a unit of mass and is about 1.660 * 10^-27 kg
Calculate the work needed to lift a block weighing 4 Newton’s a distance of 10 meters. Help me please.
Answer:
W = 40 J
Explanation:
The work done by a force is defined as the dot product of the force and displacement of the object. Therefore, the following formula can be used to find the work done:
[tex]W = F.d = Fd Cos\theta\\[/tex]
where,
W = Work Done = ?
F = Force = Weight of Block = 4 N
d = distance lifted = 10 m
θ = angle between force and displacement = 0°
Therefore,
[tex]W = (4\ N)(10\ m)(Cos\ 0^{0})[/tex]
W = 40 J
What is force? In physics class eleven
Answer:
Explanation:
In Physics, force is defined as: The push or pull on an object with mass that causes it to change its velocity. Force is an external agent capable of changing the state of rest or motion of a particular body. It has a magnitude and a directionForce is an external agent capable of changing the state of rest or motion of a particular body. It has a magnitude and a direction. The direction towards which the force is applied is known as the direction of the force and the application of force is the point where force is applied.
The Force can be measured using a spring balance. The SI unit of force is Newton(N).
17. Calculate the amount of gravitational potential energy at the top of one 4 points hill. The mass of the coaster is 500 kg. The height from the hill to the valley is 59.6 m. Use 9.81 m/s^2 as the acceleration due to gravity. Record your calculations in joules. (Hint: Gravitational PE = mgh)
A. 292.338 m/s^2
B. 3037 J
C. 82.3 kg
D. 292,338 J
Answer: D. 292,338 J
This is the correct answer :)
A string has its 4th harmonic at 31.5 Hz. What is the fundamental frequency?
Unit= Hz
Answer:
7.9Hz
Explanation:
Step one:
given data
We are told that the fourth harmonic is at 31.5 Hz
We know that harmonics are a multiple of the fundamental frequency, such that if the fundamental frequency is 25Hz, then the second harmonic is
2nd= 2*25= 50Hz
3rd= 3*25= 75Hz........and so on
Step two:
In this problem, we are told that the 4th harmonic is 31.5Hz, that is
4th= 4*f= 31.5
Divide both sides by 4 to get f
f= 31.5/4
f= 7.9 Hz
Hence the first/fundamental frequency is 7.9Hz
Answer:
its 7.9 tried it on acellus
Explanation:
Tim, with mass 73.1 kg, climbs a gymnasium rope a distance of 4.6 m. The acceleration of gravity is 9.8 m/s 2 . How much potential energy does Tim gain? Answer in units of J.
Answer:
3,295.348Joules
Explanation:
Potential Energy = mass * acceleration due to gravity * height
Given the following
Mass = 73.1kg
Acceleration due to gravity = 9.8m/s²
Distance (Height) = 4.6m
Substitute into the formula;
Potential Energy = 73.1 * 9.8 * 4.6
Potential Energy = 3,295.348Joules
Hence Tim gain 3,295.348Joules of energy
A woman of mass 50 kg is swimming with a velocity of 1.6 m/s. If she stops stroking and glides to a stop in the water, what is the impulse of the force that stops her?
Answer:
– 80 Ns.
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 50 kg
Initial velocity (u) = 1.6 m/s
Final velocity (v) = 0 m/s
Impulse (I) =?
Impulse is simply defined by the following equation:
I = Ft = m(v – u)
I = 50 (0 – 1.6)
I = 50 (–1.6)
I = – 80 Ns
Thus, the impulse of the force that stopped her is – 80 Ns.
NOTE: The negative sign indicates that the net force is in opposite direction to her movement.
27. The pressure at A is 9.5 atm and the water velocity is 10 m/s. What is the water velocity at point C
Answer:
10 m/s
Explanation:
Amateur radio operators in the United States can transmit on several bands. One of those bands consists of radio waves with a wavelength near 15.m. Calculate the frequency of these radio waves. Round your answer to 2 significant digits.
Answer:
20 MHz
Explanation:
Since speed of radio waves = speed of light = c and for a wave, v = fλ where v = speed of wave, f = frequency and λ = wavelength.
Given that λ = 15 m and v = c = 3 × 10⁸ m/s
f = v/λ
substituting the values of the variables into the equation, we have
f = v/λ = 3 × 10⁸ m/s ÷ 15 m
= 0.2 × 10⁸ Hz
= 2 × 10⁷ Hz
= 20 × 10⁶ Hz
= 20 MHz
Describe a grand challenge in today's society?
Which type of reaction does this chemical equation represent? 2Na + MgCl2 - 2NaCl + Mg
A. Synthesis
B. Decomposition
C. Single-replacement
D. Double-replacement
The answer is in fact c
The type of reaction the chemical equation represent is a decomposition reaction.
What is decomposition reaction?Decomposition reaction is a type of chemical reaction in which a large compound is broken down or degraded into simpler substances.
Therefore, type of reaction the chemical equation represent is a decomposition reaction.
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5.38 An ideal spring has the spring constant k = 440 N/m. Calculate the
distance this spring must be stretched from its equilibrium position for
25 J of work to be done.
The spring stretched 0.476 meter from equilibrium position.
The work done is given as,
[tex]workdone=\frac{1}{2}kx^{2}[/tex]
Where x is the distance stretched from equilibrium position.
Given that, [tex]k=440N/m,W=25J[/tex]
[tex]25=\frac{1}{2}*440*x^{2} \\\\x^{2} =\frac{100}{440}=0.227\\\\x=\sqrt{0.227}=0.476m[/tex]
Therefore, the spring stretched 0.476 meter from equilibrium position.
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A marksman holds a rifle with a mass of 2.57 kg loosely, so it can recoil freely. He fires a bullet with a mass of 3.65 g horizontally with a velocity relative to the ground of 318.4 m/s. What is the final kinetic energy in J of the rifle
Answer:
KE = 0.262 J
Explanation:
given data
rifle with mass Mr = 2.57 kg
bullet with mass Mb = 3.65 g
velocity relative to the ground Vb = 318.4 m/s
solution
we get here final KE of rifle that is express as
KE = 0.5 × Mr × (Vr)² ..............1
here Vr is
Mb × Vb = Mr × Vr .........2
put here value
3.65 × [tex]10^{-3}[/tex] × 318.4 = 2.57 × Vr
Vr = 0.452 m/s
now put value in eq 1 we get
KE = 0.5 × 2.57 × (0.452)²
KE = 0.262 J
A tennis player's racket applies an average force of 200. newtons to a tennis ball for 0.025 second. The average force exerted on the racket by the tennis ball
is
Answer:
200N
Explanation:
The average force exerted on the racket by the tennis ball is equal to 200 Newton.
Given the following data:
Average force = 200 NewtonTime = 0.025 secondsTo determine the average force exerted on the racket by the tennis ball, we would apply .Newton's Third Law of Motion.
Newton's Third Law of Motion states that for every action there must exist an equal but opposite reaction. Thus, Newton's Third Law of Motion is a law based on action-reaction force pairs.
In this scenario, the tennis ball would exert the same magnitude of average force on the racket in accordance with Newton's Third Law of Motion.
Average force = 200 Newton
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a tool for studying motion is called?
Answer:
phytochemical
Explanation:phytochemical is a tool for studying motion
1. The directional movement of ions by facilitated diffusion through protein channels is determined by
Answer:
The electrochemical gradient of the ion that is being transported.
Explanation:
Facilitated diffusion through protein is defined as a form of facilitated transport whereby passive movement of ions along concentration gradients are guided by the presence of other ions.
Thus, the electrochemical gradient of the ion being transported is what facilitates it
PLEASEEEEE HELP TIMED TEST!!!! Which of following correctly shows the part of the wave that represents the wavelength
Answer:
the 2nd one is the right one
Explanation:
wave length is on top
The figure 2 correctly shows the part of the wave that represents the wavelength.
What is wave?A wave is a dynamic disturbance that propagates and causes a change in equilibrium of one or more parameters in physics, mathematics, and related subjects. Quantities may oscillate regularly around an equilibrium (resting) value at certain frequency if a wave is periodic.
A travelling wave is one in which the entire waveform moves in one direction; in contrast, a standing wave is one in which two periodic waves are overlaid and move in the opposing directions.
In a standing wave, there are some points where the wave amplitude seems reduced or even zero, and these positions have null vibration amplitudes. A wave equation (standing wave field comprising two opposing waves) or a one-way wave equation (for single wave propagation in a certain direction) is frequently used to describe waves.
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Two firefighters are trying to break through a door. One firefighter is heavy, and the other is light. If they run at the same speed, which one is more likely to break through? Explain.
Answer:
The Heavier Firefighter
Explanation:
Generally, more massive objects will have more intertia than less massive objects. As such it takes more force to halt a more massive object if its moving at the same speed as a smaller object. This can also be thought of in the context of Newton's second law. The more force needed to accelerate an object means the more force the object will have.
At equal speed, the firefighter with more weight will have more momentum and exact more force which will cause breakthrough.
According to Newton's second law of motion, the force applied to an object is directly proportional to the product of mass and acceleration of the object.
F = ma
Acceleration is the change in velocity per change in time of motion.
The law can also be written as;
[tex]F = ma = \frac{mv}{t}[/tex]
Also, momentum is given as the product of mass and velocity.
P = mv
Thus, at equal speed, the firefighter with more weight will have more momentum and exact more force which will cause breakthrough.
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I need help, please.
Answer:
sorry I don't know it
Explanation:
