Answer:
C.15m/s
Explanation:
60 divided by 4 is 15
An airplane on a runway has an initial speed of 15 meters/second. What is its final velocity when it travels 600 meters on the runway with a constant acceleration of 6 meters/second2?
Answer:
86.17m/s
Explanation:
Since the motion is of constant acceleration, we can use one of the equations of motion as follows;
v² = u² + 2as
Where;
v = final velocity of the airplane
u = initial velocity of the airplane
s = distance covered by the plane
a = acceleration
From the question,
u = 15m/s
s = 600m
a = 6m/s²
Substitute these values into the equation above as follows;
v² = 15² + 2(6)(600)
v² = 225 + 7200
v² = 7425
v = √7425
v = 86.17m/s
Therefore, the final velocity of the airplane is 86.17m/s
A roller coaster starts with a speed of 4.6 m/s at a point 49 m above the bottom of a dip.
Neglecting friction, what will be the speed of the roller coaster at the top of the next
slope, which is 29 m above the bottom of the dip?
Answer:
20.5m/s
Explanation:
neglecting friction the amount of energy at the bottom equals to the amount of energy at top. Law of conservation of energy.
ME= P.E+k.E
ME= mgh+ 1/2mv*v
ME = (m* 10 *49)+(1/2m(4.6*4.6))
MEtop=500.98m
MEbottom=MEtop: in order to obey the law of conservation of energy
MEbottom=mgh+ 1/2mv*v
500.98m=m*10*29+1/2m v* v
500.98m= m(290+1/2v*v) ...cancel m by m
500.98-290=1/2v*v criss cross multiple
210.98*2=v*v
v=√421.96
v=20.5 m/s
a Porsche 911 accelerates from rest to 27 metre per second due north in 5.8 seconds the mass of the car is 1400 kg what is the magnitude and direction of the average net force
Answer:
The average force has a magnitude 6524 N due north.
Explanation:
The average net force F = ma where m = mass of car = 1400 kg and a = acceleration.
a = (v - u)/t where u = initial velocity of car = 0 m/s (since it starts from rest)
v = final velocity of car = 27 m/s due north and t = time of motion = 5.8 s
a = (27 m/s - 0 m/s)/5.8 s = 27 m/s ÷ 5.8 s = 4.66 m/s
Since the direction of the velocity change is the direction of the acceleration, the acceleration is 4.66 m/s due north.
The average force, F = ma = 1400 kg × 4.66 m/s = 6524 N
Since the acceleration is due north, the average force takes the direction of the acceleration.
So the direction of the average force is due north
The average force has a magnitude 6524 N due north.
Which of the following is an example of the Doppler effect? A water bug on the surface of a pond is producing small ripples in the water. The bug is not moving. A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. Scientists measure the speed of light and find that it is constant. The gravitational pull of two objects on each other
Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
The phenomenon of Doppler effects is generally applicable to both sound and light.
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc.
Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
This should be the correct answer.
21. A toy car starts from rest and accelerates at 1.50 m/s’ [E] for 5.25 s. What is the final
velocity, V, of the car? Show your work.
Answer: The final Velocity, V, of the car is 7.9m/s
Explanation:
Given the following :
Toy car starts from rest, therefore,
Initial Velocity (u) = 0
Acceleration (a) = 1.5m/s^2 E for time, t = 5.25s
Final velocity (V) of the car =?
Using the motion equation:
v = u + at
Where v = final Velocity
u = Initial Velocity
a = acceleration
t = time
v = 0 + 1.5(5.25)
v = 0 + 7.875
v = 7.875m/s
v = 7.9m/s
The magnitude of the electric potential depends on which factors?
O A. Mass and amount of charge
O B. Mass and distance
O C. Distance and amount of charge
O D. Density and amount of charge
Answer:
C
Explanation:
It is directly propotional to the amount of charge and inversly propotional to distance.
Answer:
C. Distance and amount of charge
Explanation:
The magnitude of the electric potential depends on which factors?
Distance and amount of charge
whats the texture of copper wire
Copper is a reddish orange, soft metal with a bright metallic luster. It is an excellent conductor of heat and electricity. Copper surfaces when exposed to air gradually turns to a dull, brownish color.
A toaster oven draws 300.0 watts of power. If it is plugged into an outlet with a voltage of 115 volts, what current is in the toaster's circuit?
OA 3.45 10% amps
ОВ.
415 amps
Ос.
285 amps
OD
2.61 amps
Answer:
I = 2.61 A
Explanation:
It is given that,
Power of a toaster is 300 watts
It is plugged into an outlet with a voltage of 115 volts
We need to find the current in the toaster's circuit.
The electrical power is given by the formula as follows :
P = V I
I is electric current
[tex]I=\dfrac{P}{V}\\\\I=\dfrac{300}{115}\\\\I=2.61\ A[/tex]
So, 2.61 A of current is in the toaster's circuit.
Answer: D.
2.61 amps
Explanation: edmentum
helppppp me it's urgent please
the last one is the light will move in some manner not determined by the information here.
Light bends away from the normal, because it's moving from higher to lower refractive index.
Same bend-direction as when it goes from water into air.
Los primeros vuelos de prueba del transbordador espacial usaban un "planeador" (con masa de 980 kg incluyendo el piloto). Después de un lanzamiento horizontal a 480 km/h a una altitud de 3500 m, el planeador finalmente aterrizaba con una rapidez de 210 km/h ¿Cuál era la fuerza promedio que la resistencia del aire ejercía sobre él cuando entraba con un ángulo de planeo constante de 12° con respecto a la Tierra?
Answer:
La fuerza promedio que ejerce la resistencia del aire sobre el planeador cuando ingresa con un ángulo de planeo constante de 12 ° con respecto a la Tierra es 9613.8 N
Explanation:
Los parámetros dados son;
Masa del planeador = 980 kg.
Velocidad de lanzamiento horizontal = 480 km / h
Altitud de lanzamiento = 3500 m.
Velocidad de aterrizaje final = 210 km / h
Ángulo de deslizamiento, θ = 12 °
La ecuación para el equilibrio de fuerzas.
L · cos (θ) + D · sin (θ) = W
L · sin (θ) + D · cos (θ)
Dónde:
L = fuerza de elevación
D = fuerza de arrastre
W = Peso del "planeador"
W = Masa del "planeador" × Aceleración debido a la gravedad = 980 kg × 9.81 m / s²
W = 9613.8 N
Por lo tanto, tenemos;
L · cos (12) + D · sin (12) = 9613.8 ,,,,,,,,,,,,, (1)
L · sin (12) = D · cos (12) ,,,,,,,,,,,,, (2)
De la ecuación (2), tenemos;
L = D · (cos (12)/sin (12))
Sustituyendo el valor de L = D · (cos (12) / sin (12)) en la ecuación (1), se obtiene;
D · (cos (12)/sin (12)) · cos (12) + D · sin (12) = 9613.8
D = 9613.8/((cos (12)/sin (12)) · cos (12) + sin (12)) = 1998.82 N
L = D · (cos (12)/sin (12)) = 1998.82 · (cos (12)/sin (12)) = 9403.72 N
Por lo tanto, la fuerza da la fuerza promedio que la resistencia del aire ejerce sobre el planeador cuando ingresa con un ángulo de planeo constante de 12 ° con respecto a la Tierra;
F = √ (L² + D²) = √ (9403.72² + 1998.82²) = 9613.8 N.
Which two substances could be produced in a combustion reaction?
A. Carbon dioxide and oxygen
B. Carbon dioxide and water
C. Heptane and water
D. Heptane and oxygen
Answer: B. Carbon dioxide and water
Explanation: Combustion simply refers to burning. A combustion reaction may thus be explained as a chemical process which involves the reaction between a substance and an oxidizer usually oxygen gas. The combustion reaction in most cases involves the reaction between hydrocarbons which are combustible compounds and oxygen gas. The reaction between the combustible compound and oxygen gas is then followed by the release of energy, with the product being carbondioxid and water. Below is an example of combustion reaction.
Combustion the Methane CH4.
Here, CH4 reacts with oxygen gas(O2) to produce carbondioxide and water.
CH4 + 2O2 ------> CO2 + 2H2O
Answer:
Correct answer B
Explanation:
Just took quiz
Two projectiles are thrown from the same point with the velocity of49ms-1. First is
projected making an angle with the horizontal and the second at an angle of (90- ). The
second is found to rise 22.5m higher than the first. Find the heights to which each will rise?
Answer:
Height of the first projectile = 49.98 m
Height of the second projectile = 72.52 m
Explanation:
From the given information;
Two projectiles are thrown from the same point with the velocity of49m/s
First is projected making an angle θ with the horizontal
and the second at an angle of 90 - θ.
Thus; for the first height to the horizontal; we have;
[tex]H_1 = \dfrac{v^2 sin^2 \theta}{2g}[/tex] ----- (1)
the second height in the vertical direction is :
[tex]H_2 = \dfrac{v^2 cos^2 \theta}{2g}[/tex] -----(2)
However; the second is found to rise 22.5 m higher than the first; so , we have :
[tex]\dfrac{v^2 cos^2 \theta}{2g}= 22.5 + \dfrac{v^2 sin^2 \theta}{2g}[/tex]
Let's recall that :
Cos²θ = 1 - Sin²θ
Replacing it into above equation; we have:
[tex]\dfrac{v^2}{2g} - \dfrac{v^2 sin^2 \theta}{2g}= 22.5 + \dfrac{v^2 sin^2 \theta}{2g}[/tex]
[tex]\dfrac{v^2}{2g} - 22.5 = \dfrac{v^2 sin^2 \theta}{g}[/tex]
[tex]\dfrac{1}{2 } \dfrac{v^2}{g} - 22.5 = \dfrac{v^2 sin^2 \theta}{g}[/tex]
[tex]\dfrac{1}{2 } - \dfrac {9.8 \times 22.5}{(49)^2} = sin^2 \theta[/tex]
[tex]\dfrac{1}{2 } - \dfrac {220.5}{2401} = sin^2 \theta[/tex]
[tex]sin^2 \theta= 0.408[/tex]
From (1);
[tex]H_1 = \dfrac{v^2 sin^2 \theta}{2g}[/tex]
[tex]H_1 = \dfrac{49^2 \times 0.408}{2*9.8}[/tex]
[tex]H_1 = \dfrac{979.608}{19.6}[/tex]
[tex]\mathbf{H_1 =49.98 \ m }[/tex]
Height of the first projectile = 49.98 m
Similarly;
From(2)
[tex]H_2 = \dfrac{v^2 cos^2 \theta}{2g}[/tex]
[tex]H_2 = \dfrac{v^2 (1-sin^2 \theta)}{2g}[/tex]
[tex]H_2 = \dfrac{49^2 (1-0.408 )}{2 \times 9.8}[/tex]
[tex]H_2 = \dfrac{2401 (0.592 )}{19.6}[/tex]
[tex]H_2 = \dfrac{1421.392}{19.6}[/tex]
[tex]\mathbf{H_2 = 72.52 \ m}[/tex]
Height of the second projectile = 72.52 m
Un avión vuela a una velocidad de 900 km/h. Si tarda en viajar desde Canarias hasta la península 180 s ¿qué distancia recorre en ese tiempo?
Answer:
El avión recorrió 45 km en los 180 s.
Explanation:
La relación entre velocidad, distancia y tiempo se da de la siguiente manera;
[tex]Velocidad= \dfrac{Distancia}{Hora}[/tex]
Por lo cual los parámetros dados son los siguientes;
Velocidad = 900 km/h = 250 m / s
Tiempo = 180 s
Estamos obligados a calcular la distancia recorrida
De la ecuación para la velocidad dada arriba, tenemos;
Distancia recorrida = Velocidad pf viaje × Tiempo de viaje
Distancia recorrida = 900 km/h × 180 s = 900
Distancia recorrida = 900 km/h × 1 h/60 min × 1 min/60 s × 180 s = 45 km
Por lo tanto, el avión viajó 45 km en 180 s.
Question 1 of 10
2 Points
What is the SI unit for gravitational potential energy?
A. Newton
B. Joule
C. Meter
D. Watt
Answer:
Joule
Explanation:
As any unit of energy (kinetic, potential, etc.), the gravitational potential energy has SI units of Joule. This s the work done by a force of 1 Newton to displace an object 1 meter in the direction of application of the force.
If a locomotive uses steam at
100°C, and dumps heat into air
at 220°C. what is the highest
possible efficiency it could have?
Answer:
79%
Explanation:
The following data were obtained from the question:
Input temperature = 100°C
Output temperature = 22°C
Efficiency =.?
Next, we shall convert the temperature from celsius to Kelvin temperature. This is illustrated below:
T (K) = T (°C) + 273
Input temperature = 100°C
Input temperature = 100°C + 273 = 373K
Output temperature = 22°C
Output temperature = 22°C + 273 = 295K
The efficiency of the locomotive can be obtained as follow:
Input temperature = 373K
Output temperature = 295K
Efficiency =.?
Efficiency = output /input x 100
Efficiency = 295/373 x 100
Efficiency = 79%
Therefore, the efficiency of the locomotive is 79%.
Rachel and Andrew are riding on a ferry boat traveling east at 3.5 m/s. Rachel rolls a marble with a velocity of 0.95 m/s north, straight across the deck of the boat to Andrew. What is the velocity of the marble relative to the water?
Answer:
The velocity of the marble relative to the water is 3.63 m/s
Explanation:
The information given are;
The velocity of the ferry relative to the water = 3.5 m/s
Direction of motion of the ferry = East
The velocity of the marble (on the ferry) relative to the ferry = 0.95 m/s
The direction of the marble = North
The (resultant) velocity of the marble relative to the water, [tex]v_R[/tex], is found as follows;
Resolution of the velocities;
Velocity of the ferry = 3.5·i + 0·j
Velocity of the marble = 0·i + 0.95·j
[tex]v_R[/tex] = Combined (resultant) velocity = √(3.5² + 0.95²) = 3.63 m/s
The velocity of the marble relative to the water = 3.63 m/s.
A ball is being rolled by a normal push of 180N. It is opposed by friction which has a force of 61N and air resistance which has a force of 23N. Calculate the resultant force.
Resultant force is basically the force left after everything is added.
if a ball is being pushed one one side with 180N, and being pushed on teh opposite side with 84N (I added friction and air resistance since they're acting on the same side), then the resultant force would be:
180N - 84N = 96N (you can determine whether it's positive or negative based on the direction of the vector)
What engineering problem was presented in the study?
A. The lightbulbs were too bright.
B. The lightbulbs were too dim.
C: The lightbulbs were exploding after several minutes of use.
D. The lightbulbs were burning out after only a few hours of use.
Answer:
The lightbulbs were exploding after several mins of use
Explanation:
Answer:
the lightbulbs were exploding after several minutes of use
Explanation:
a p e x :))
NEED HELP!! WILL GIVE BRAINIEST!! When a driver presses the brake pedal, his car can stop with an acceleration of -5.4 meters per second squared. how far will the car travel while coming to a complete stop if its initial speed was 25 meters per second?
Answer:
d = 57.87 m
Explanation:
It is given that,
Acceleration of car due to applied brake is [tex]-5.4\ m/s^2[/tex]
Its initial speed was 25 m/s
Its final speed was 0 as its comes to rest.
Leat d is the distance covered by the car. It can be calculated using third equation of kinematics as :
[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{0^2-(25)^2}{2\times (-5.4)}\\\\d=57.87\ m[/tex]
So, the distance covered by the car is 57.87 m.
Answer:
d = 57.87 m
Explanation: have a nice day :)
I need a story about kepler's laws for a child, something a child would understand. And i'd like it to be okay for someone if I copy anhd paste it or else my parents are gonna kill me and my teacher will be very disappointe, this is for summer school.
Answer:
(1) The orbits are ellipses, with focal points ƒ1 and ƒ2 for the first planet and ƒ1 and ƒ3 for the second planet. The Sun is placed in focal point ƒ1.
(2) The two shaded sectors A1 and A2 have the same surface area and the time for planet 1 to cover segment A1 is equal to the time to cover segment A2.
(3) The total orbit times for planet 1 and planet 2 have a ratio a13/2 : a23/2
Answer:
g the day off and I will be there at work and I will be there at work and I will
Explanation:
you are not going to be able to make it to the meeting tonight but I can tomorrow
how does enormous energy get released from the sun
Answer:
By nuclear fission
Explanation:
The sun generates enormous energy through the process of nuclear fusion.
The core or the innermost part of the sun is characterized by high temperature and pressure. These two factors cause the separation of nuclei from electrons and the fusion of hydrogen nuclei to form a helium atom.
During the fusion process, energy is released.
A ball is moving up an inclined plane, when it's velocity changes from 15m/s to 7m/s in 3 seconds . What is the acceleration.
Explanation:
[tex]a = \frac{change \: in \: velocity}{change \: in \: time} [/tex]
[tex]a = \frac{v - u}{t} [/tex]
[tex]v = 7 {ms}^{ - 1} [/tex]
[tex]u = 15 {ms}^{ - 1} [/tex]
[tex]t = 3 \: seconds[/tex]
[tex]a = \frac{7 - 15}{3} [/tex]
[tex]a = \frac{ - 8}{3} [/tex]
[tex]a = - 2.67 \: {ms}^{ - 2} [/tex]
Study the image of earths layer which statement correctly compares the thicknesses of earths layers
This question is incomplete because the options are missing; here is the complete question:
Study the image of the Earth's layer which statement correctly compares the thicknesses of earths layers
A. Earth’s mantle is thinner than its oceanic crust.
B. Earth’s outer core is thicker than its mantle.
C. Earth’s continental crust is thicker than its lithosphere.
D. Earth’s lithosphere is thinner than its asthenosphere.
The answer to this question is D. Earth’s lithosphere is thinner than its asthenosphere.
Explanation:
The image shows the different layers that are part of Earth, as well as the thickness of each layer, in kilometers. In this, the thickest layer is the Mantle that is almost 2900 kilometers; this is followed in thickness by the outer and the inner core.
Additionally, other layers such as the continental/oceanic crust, the asthenosphere, and the lithosphere that are near the surface are thinner. About this, it can be concluded the lithosphere is thinner than the asthenosphere because the lithosphere has a thickness of 100 km, while the asthenosphere thickness is 660km. This makes option D the correct.
Example
Rain appears to fall vertically to a man walking at a rate of 3km/h. At
a speed of 6 km/h, it appears to meet him at an angle of 45° of vertical.
Find out the speed of rain.
Answer:
4.24 km/h
Explanation:
When the man walks at a rate of 3 km/h, the rain appears to fall vertically, which means it has the same horizontal rate, 3 km/h.
When the man walks at a rate of 6 km/h, the rain's horizontal velocity relative to the man is now 6 km/h − 3 km/h = 3 km/h. The rain meets the man at a 45 degree angle, so the vertical velocity is also 3 km/h.
Therefore, the total speed is:
v = √((3 km/h)² + (3 km/h)²)
v = 4.24 km/h
please help
The statement "46 m, East" refers to the
of an object.
velocity
distance
displacement
speed
acceleration
Answer:
Displacement
Explanation:
Displacement is a vector quantity i.e it has both magnitude and direction. The direction is indicated with compass bearing i.e North, South, East or West or you could have North East, North West, South West, South East.
Using the formula W = mg, how many milliliters of water with a density of 1g/mL are required to weigh 0.75 newtons and g = 9.81 m/s2? Round to the nearest tenth. (Note: The mass will be in kg in your answer, thus convert to g and then to mL.) Answer: mL
Given that,
Weight = 0.75 N
Acceleration due to gravity = 9.81 m/s²
Density of water = 1 g/ml
We need to calculate the volume of water
Using formula of weight
[tex]W=mg[/tex]
[tex]W=\rho Vg[/tex]
[tex]mg=\rho\times V\times g[/tex]
Where, V = volume
g = acceleration
m = mass
Put the value into the formula
[tex]0.076\times 9.8\times10^3=1\times V\times9.8[/tex]
[tex]V= \dfrac{0.076\times 9.8\times10^3}{1\times9.8}[/tex]
[tex]V=76\ ml[/tex]
Hence, The volume of water is 76 mL.
Answer:
76.5mL
Explanation:
w = mg
0.75N = m * 9.81
m = 0.75 / 9.81 = 0.0765 kg
The mass in grams is 0.0765 * 1000 = 76.5g
At a density of 1 g/mL,
76.5g ÷ 1g/ml = 76.5mL
Describe the method you would use to measure the cicrumfrence of a cylinder using a thread and a meter
rule(4mk)
0)
Answer:
I take the thread and wrap it round the cylinder until it goes round the circumference of the cylinder.
Explanation:
I take the thread and wrap it round the cylinder until it goes round the circumference of the cylinder.
I then cut the thread at this length and extend it out on a table or floor.
I then place the length of the thread along the meter rule and mark of the position of its tip and bottom along the meter rule.
The difference between the bottom and top points is the circumference of the cylinder.
If the thread is longer than the meter rule, i mark off where the the length of the meter rule stops along the thread and then place the meter rule at that point and then mark off where the length of the thread stops.
The circumference of the cylinder is then 1 meter plus the extra measurement along the meter rule.
Choose all correct statements: Refractive index of medium A with respect to medium B is 4/3 and refractive index of medium A with respect to medium C is 3/2. Medium B is denser than medium C When light travels from B to C light bends away from the normal Refractive index of C with respect to B is 8/9 Ratio of speed of light in medium B to the speed of light in medium A = 4/3
Answer:
Medium B is denser than medium C
When light travels from B to C light bends away from the normal .
Refractive index of C with respect to B is 8/9
Ratio of speed of light in medium B to the speed of light in medium A = 4/3
Explanation:
Refractive index of medium A / Refractive index of medium B = 4/3
Refractive index of medium A / Refractive index of medium C = 3/2
Dividing ,
Refractive index of medium B / Refractive index of medium C
= 3/2 x 3/4
= 9 / 8
Refractive index of medium B > Refractive index of medium C
Refractive index of C with respect to B is 8/9
speed of light in medium B / the speed of light in medium A
= refractive index of A / refractive index of B = 4 / 3
SPEAR is a storage ring at the Stanford Linear Accelerator which has a circulating beam of electrons that are moving at nearly the speed of light (2.998 108 m/s). If a similar ring is about 80.0 m in diameter and has a 0.59 A beam, how many electrons are in the beam
Answer:
n = 3.1x10¹²
Explanation:
To find the number of electrons we need to find first the charge (q):
[tex] I = \frac{q}{\Delta t} \rightarrow q = I*\Delta t [/tex] (1)
Where:
I: is the electric current = 0.59 A
t: is the time
The time t is equal to:
[tex]v = \frac{\Delta x}{\Delta t} \rightarrow \Delta t = \frac{\Delta x}{v}[/tex] (2)
Where:
x: is the displacement
v: is the average speed = 2.998x10⁸ m/s
The displacement is equal to the perimeter of the circumference:
[tex] \Delta x = 2\pi*r = \pi*d [/tex] (3)
Where d is the diameter = 80.0 m
By entering equations (2) and (3) into (1) we have:
[tex]q = I*\Delta t = I*\frac{\Delta x}{v} = \frac{I\pi d}{v} = \frac{0.59 A*\pi*80.0 m}{2.99 \cdot 10^{8} m/s} = 4.96 \cdot 10^{-7} C[/tex]
Now, the number of electrons (n) is given by:
[tex] n = \frac{q}{e} [/tex]
Where e is the electron's charge = 1.6x10⁻¹⁹ C
[tex] n = \frac{q}{e} = \frac{4.96 \cdot 10^{-7} C}{1.6 \cdot 10^{-19} C} = 3.1 \cdot 10^{12} [/tex]
Therefore, the number of electrons in the beam is 3.1x10¹².
I hope it helps you!
A high diver of mass 74.0 kg jumps off a board 9.00 m above the water. If his downward motion is stopped 2.50 seconds after he enters the water, what average upward force did the water exert on him
Answer:
1120 N
Explanation:
The velocity with which he hits the water can be found with kinematics:
v² = v₀² + 2aΔy
v² = (0 m/s)² + 2 (-9.8 m/s²) (-9.00 m)
v = -13.3 m/s
Or it can be found with conservation of energy.
PE = KE
mgh = ½ mv²
v = √(2gh)
v = √(2 × -9.8 m/s² × -9.00 m)
v = -13.3 m/s
Sum of forces on the diver after he hits the water:
∑F = ma
F − mg = m Δv/Δt
F − (74.0 kg) (9.8 m/s²) = (74.0 kg) (0 m/s − (-13.3 m/s)) / (2.50 s)
F = 1120 N