When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 84.0-kg man just before contact with the ground has a speed of 6.82 m/s. (a) In a stiff-legged landing he comes to a halt in 4.56 ms. Find the magnitude of the average net force that acts on him during this time. (b) When he bends his knees, he comes to a halt in 0.254 s. Find the magnitude of the average net force now. (c) During the landing, the force of the ground on the man points upward, while the force due to gravity points downward. The average net force acting on the man includes both of these forces. Taking into account the directions of the forces, find the magnitude of the force applied by the ground on the man in part (b).
Answer:
a) F = 1.26 10⁵ N, b) F = 2.255 10³ N, c) F_ {soil} = 3078 N
Explanation:
For this exercise we will use the relationship between momentum and moment
I = Δp
F t = p_f -p₀
a) with stiff legs, final speed is zero, initial velocity is down
Ft = 0-p₀
F = m v / t
let's calculate
F = 84.0 6.82 / 4.56 10⁻³
F = 1.26 10⁵ N
b) bending the legs
let's calculate
F = 84.0 6.82 / 0.254
F = 2.255 10³ N
c) It is requested to calculate the force of the ground on the man
∑ F = F_soil -W
F_soil = F + W
F_ {soil} = 2.255 103 + 84 9.8
F_ {soil} = 3078 N
an organism that cannot make its own food called
Answer:
heterotroph
Explanation:
Answer:
a predator cannot make its own food
What is the speed of a 1600kg car if its momentum is 120,000kgms?
Answer:
Velocity of car = 75 m/s
Explanation:
Given:
Mass = 1,600 kg
Momentum = 120,000kgm/s
Find:
Velocity of car
Computation:
Velocity = Momentum / mass
Velocity of car = 120,000 / 1,600
Velocity of car = 75 m/s
Suppose to a scientist was able to construct a barometer with a liquid being twice denser than mercury, then how would the liquid raise at standard pressure?
Answer:
h = h₀/2, the liquid column rises half the height
Explanation:
Pressure is defined as force per area,
P = F / A
in a barometer the force is the weights of the liquid column
F = W = mg
P = m g/A
if we use the definition of density
ρ = [tex]\frac{m}{A h}[/tex]
[tex]\frac{m}{A}[/tex] = ρ h
we substitute
P = ρ g h
Let's use the index o for the mercury
P₀ = ρ₀ g h₀
when we change the liquid for another with
ρ = 2ρ₀
the pressure expression is
P = 2ρ₀ g h
in the problem they indicate that the pressure is equal to the initial P = P₀
we substitute
ρ₀ g h₀ = 2ρ₀ g h
h₀ = 2h
h = h₀/2
the liquid column rises half the height
Forms of energy! Write a brief summary about each form of energy below.
Mechanical:
Thermal:
Chemical:
Electromagnetic:
Electrical:
Nuclear:
Answer:
Hope this helps!! :D
Explanation:
Mechanical energy is power that an object gets from its position and motion. the energy released during nuclear fission or fusion, typically to make electricity.
Thermal energy is the energy given off by hot things like fire.
Chemical energy is energy stored in the bonds of chemical compounds.
Electromagnetic energy is a form of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel.
Electrical energy is energy derived from electric potential energy or kinetic energy.
Nuclear energy is the energy released during nuclear fission or fusion, typically used to generate electricity.
A 500 kg car traveling at 20 m/s rear ends another car of 600 kg at rest. The collision is great enough that the two cars stick together after they collide. How fast will both cars be going after the collision?
Answer: its 50
Explanation:
im waffling does anybody have syrup
Complete the following sentence.
An animal’s genetic and observable traits are called the
_and_
dont have options
Answer:
Dominant and recessive
Explanation:
This is like 6th-grade stuff man
Kyra and Pari are timing how long it takes for 1 g of sugar to dissolve in hot water. Kyra records a time of 24.3 seconds. Pari records a time of 24 seconds. Whose reading is more precise? Why?
A circus stuntman holds himself straight out by his arms from a vertical pole. If the stuntman's center of gravity is located 0.75 m away from the pole and he weights 650 N, how much force do is arms have to apply if they exert their force upwards at 0.10 m away from the pole? [4875 N]
Answer: 4875 N
Explanation:
Given
Stuntman weight is [tex]W=650\ N[/tex]
His center of gravity is located at [tex]x=0.75\ m[/tex] away from pole
If he applies an upwards force at 0.10 m away from the pole
Suppose F is the applied force
To remain vertical, the torque of weight must be canceled by the vertical force
[tex]\Rightarrow 650\times 0.75-F\times 0.10=0\\\\\Rightarrow 650\times 0.75=F\times 0.10\\\\\Rightarrow F=\dfrac{487.5}{0.10}=4875\ N[/tex]
What are the 3 basic parts of an atom and what are their charges?
Answer:
electrons neutrons and protons
Explanation:
electron are negative
nuetron are neutral
protons are positive
Which factors could be potential sources of error in the experiment? Check all that apply.
energy lost in the lever due to friction
color of the soda bottle used in the experiment
visual estimation of height of the beanbag
temperature of the lab at the time of the experiment
position of the fulcrum for the lever affecting transfer of energy
Answer:
1. energy lost in the lever due to friction
3. visual estimation of height of the beanbag
5. position of the fulcrum for the lever affecting transfer of energy
Explanation:
Edge 2021
The factors that could be potential sources of error in the experiment are
Energy lost in the lever due to frictionVisual estimation of height of the beanbag Position of the fulcrum for the lever affecting transfer of energyOptions A,C,E
What is an error in the experiment?Error in the experiment is simply defined as the inaccuracies that prevent us from seeing an entirely correct measurement.
In conclusion, Errors in experiments are inevitable but the average is used to curtail them.
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A student makes a homemade resistor from a graphite pencil 5.00 cm long, where the graphite is 0.05 mm in diameter. The resistivity of the graphite is rho=1.38×10−5Ω/mrho=1.38×10−5Ω/m . The homemade resistor is place in series with a switch, a 10.00-mF uncharged capacitor and a 0.50-V power source. (a) What is the RC time constant of the circuit? (b) What is the potential drop across the pencil 1.00 s after the switch is closed?
Answer:
(a) RC time constant of the circuit is 6.9 × 10⁻⁶ ms
(b) The potential drop across the capacitor 1.00 s after the switch is closed is 0 V
Explanation:
The given parameters are
The length of the graphite pencil, L = 5.00 cm
The diameter of the graphite, D = 0.05 mm
The resistivity of the graphite, ρ = 1.38 × 10⁻⁵ Ω/m
The capacitance of the capacitor, C = 10.0 mF
The voltage of the power source, V = 0.50-V
(a) The RC time constant of the circuit, τ, is given as follows;
τ = R × C
Where;
R = The resistance of the graphite = L × ρ
C = The capacitance of the capacitor
∴ R = 5.00 cm × 1.38 × 10⁻⁵ Ω/m = 6.9 × 10⁻⁷ Ω
RC time constant of the circuit, τ = 6.9 × 10⁻⁷ Ω × 10.0 mF = 6.9 × 10⁻⁶ ms
RC time constant of the circuit, τ = 6.9 × 10⁻⁶ ms
(b) The potential drop after t = 1.00 s is given as follows;
[tex]i = \dfrac{V}{R} \cdot e^{-\dfrac{t}{R\cdot C} }[/tex]
Where;
I = The current in the circuit
V = The voltage in the circuit = 0.50 V
R = resistance in the circuit = 6.9 × 10⁻⁷ Ω
C = The series capacitance = 10.0 mF
t = The time taken = 1.00 s
Plugging in the variable values, gives;
[tex]I = \dfrac{0.5}{6.9 \times 10^{-7}} \cdot e^{-\dfrac{1.00}{6.9 \times 10^{-7}\times 10.0 \ mF} } = 0[/tex]
V(1) = I·R = 0 × R = 0
The potential drop across the capacitor 1.00 s after the switch is closed, V(1) = 0 V
What would be the wavelength of the sound
when it travels through the concreate wall
with the frequency of 4500 hertz?
Answer: 0,96 m
Explanation: speed in concrete is 4300 m/s
According to wave equation speed v = lambda × frequency
Lambda = speed /frequency
will mark the brainiest
why is water poor conductor of heat but food conductor of electricity? pls explain
Explanation:
water contains dissolved salts which can create ions
Answer:
Water is a poor conductor of heat: Most of the heat will move in a convection current within the water at the top of the test tube, only a small fraction of it will conduct down to the ice cube.
Water doesn't need to have a large amount of impurities to act as a good conductor of electricity; even a small amount of ions can enable a source of water to conduct electric current. In a nutshell, water is able to conduct electricity due to the dissolved ions and impurities within it.
Question: Why do you think the door opens, even if it is pushing back at equal force?
If a force of 3000 N can move a crate at an acceleration of 9.2 m/s2, what is the mass of the object?
Answer:
326 kg
Explanation:
m=f/a
3000/9.2=326 kg
AWARDING BRAINLIEST
Compared to water, most metals have low specific heats.
Please select the best answer from the choices provided
T
F
Answer:
it is true
Explanation:
i think so
not really sure
Alannah added a strip of zinc to a beaker containing a solution of copper
sulfate, as shown in the photo. She expected to observe the immediate
formation of solid copper in the beaker but saw no evidence of a reaction.
Alannah predicted that the reaction was happening too slowly to observe.
Which statement could best explain this result?
The solution of copper sulfate was too cold
Explanation:
The lack of an observable reaction when adding a zinc strip to a copper sulfate solution could be due to the zinc not being reactive enough, the reaction occurring too slowly, or an experimental error.
What is the lack of an observable reaction?The lack of an observable reaction refers to a situation where no visible or measurable change occurs when two or more substances are mixed or brought into contact with each other, even though a reaction was expected based on the chemical properties of the substances involved.
Here in the Question,
The lack of an observable reaction when Alannah added a strip of zinc to a beaker containing a solution of copper sulfate could be due to the following reasons:
Zinc and copper sulfate do not react: It is possible that the zinc strip and copper sulfate solution do not react with each other, leading to no observable change. This could occur if the zinc strip is not reactive enough to displace the copper in the copper sulfate solution.
Reaction is slow: Another possibility is that the reaction between zinc and copper sulfate is occurring but is happening too slowly to be observed. In this case, the reaction rate may be too low to produce an observable amount of solid copper in the beaker in a short period of time.
Experimental error: It is also possible that an error was made during the experiment that prevented the expected reaction from occurring. For example, the concentration of the copper sulfate solution may have been too low, or the zinc strip may have been coated with a layer of oxide that prevented it from reacting with the solution.
Therefore, Zinc may not be sufficiently reactive, the reaction may proceed too slowly, or there may have been a mistake in the experiment if there was no detectable reaction when a zinc strip was added to a copper sulphate solution.
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A scooter acquires a speed of 36km/ h in 5s just after the start. Calculate the acceleration of the scooter
Answer:
We need to convert seconds to hours:
5s= (5/60)min= 0.08min=(0.08/60)h=0.001h
a=v/t=36/0.001=36.000km/h^2
briefly discuss university need based scholarships and explain them.
Answer: Scholarships are given to reduce the burden of finance to be payed for academics and learning.
Explanation:
The need based scholarships are given in the following matters:
1. Research based scholarships: Scholarships should be given to meritorious students to conduct research in a particular discipline.
2. Student fails to submit fees: The student if meritorious and family is not able to fees then university can either postpone the date for fees payment or can give some concession in fees or fund the student fees for a tenure. It is a kind of scholarship for meritorious students.
3. Teacher scholarships: Teachers are allowed to learn new teaching methodologies with other institutions so that they can help students to learn well. They are provided with scholarships to avail admission in those institutions.
Which graph best represents the relationship between KE and speed?
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward.
A graph with vertical axis K E and horizontal axis Speed with a concave line sloping sharply upward.
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply downward.
A graph with vertical axis K E and horizontal axis Speed with a curved line going first upward and then downward.
A graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward.
Relationship between kinetic energy and speedThe kinetic energy of an object is directly proportional to the square of its speed which means that if kinetic energy of an object increases the speed of that object is also increases and vice versa so we can conclude that graph with vertical axis K E and horizontal axis Speed with a straight line sloping sharply upward is the right answer.
Learn more about speed here: https://brainly.com/question/4931057
Answer:
The correct answer is:
B.)
Explanation:
I did the assignment on Edge, 2022.
(See the attachment below.)
Hope this helped, good luck on the quiz! :D
why must the lamina swing freely in physics
Answer:
Unless the lamina is able to move freely under the influence of gravity, you do not know where to draw that line.
Explanation:
7. a. How is speed related to kinetic energy?
Increase in speed leads to increase in kinetic energy
if a car exerts a area of 3m and a force of 9N what is the pressure exerted by car
Answer:
P = 3 Pa
Explanation:
Given that,
Force exerted by the car, F = 9 N
The area of the car, A = 3 m²
We need to find the pressure exerted by the car. We know that pressure is equal to the force per unit area such that,
[tex]P=\dfrac{F}{A}\\\\P=\dfrac{9\ N}{3\ m^2}\\\\P=3\ Pa[/tex]
So, the pressure exerted by the car is equal to 3 Pa.
Two people are talking at a distance of 3.0 m from where you are, and
you measure the sound intensity as 1.1'10 W/m. Another student
is 4.0 m away from the talkers. Calculate a reasonable estimate for the
sound intensity that the other student measures.
A) 62' 10-8 W/m2
B) 1.5'10-7 W/m2
8.3' 10-8 W/m2
D) 7.8'10-7 W/m2
Answer:
The sound intensity that the other student measure, I₂ is expected to be;
A) 6.2 × 10⁻⁸ W/m²
Explanation:
The measure of sound intensity is given by the following formula;
[tex]I = \dfrac{P}{4 \cdot \pi \cdot R^2}[/tex]
[tex]\dfrac{I_2}{I_1} = \dfrac{R_1^2}{R_2^2}[/tex]
Where;
I = The intensity
R = The radius
P = The power of the sound
Whereby we have;
The distance of the two people talking, R₁ = 3.0 m
The measure of the sound intensity, I₁ = 1.1 × 10⁻⁷ W/m² (from an online source)
The distance of the other student from the two people talking, R₂ = 4.0 m
Therefore, the estimate of the sound intensity, I₂, is given as follows;
[tex]{I_2} = \dfrac{R_1^2}{R_2^2} \times {I_1}[/tex]
[tex]{I_2} = \dfrac{(3.0 \, m)^2}{(4.0 \, m)^2} \times 1.1 \times 10^{-7} \ W/m^2 = 6.1875 \times 10^{-8} \ W/m^2[/tex]
I₂ = 6.1875 × 10⁻⁸ W/m²
∴ The sound intensity that the other student measure, I₂ ≈ 6.2 × 10⁻⁸ W/m²
What is the transfer of energy that occurs when a force causes an object to move?
O Energy
Force
Power
O Work
Answer:
huh? I think it's Power.....
Plzzzz help hurry plzzzzzz plzzz
Answer:
The first one is C, and the second is not clear please show another photo
Explanation:
A cement mixer with a radius of 2 m spins with a tangential velocity of 0.4 m/s. Determine the centripetal acceleration of a piece of dried cement stuck to the inside wall of the mixer.
Answer:
[tex]a=0.08\ m/s^2[/tex]
Explanation:
Given that,
The radius of the mixer, r = 2 m
Tangential velocity of the mixer, v = 0.4 m/s
We need to find the centripetal acceleration of a piece of dried cement stuck to the inside wall of the mixer. The formula for the centripetal acceleration is given by :
[tex]a=\dfrac{v^2}{r}\\\\a=\dfrac{(0.4)^2}{2}\\\\a=0.08\ m/s^2[/tex]
So, the centripetal acceleration is equal to [tex]0.08\ m/s^2[/tex].
A student bangs a brick at the head of a table. Three students are positioned equal distance from the head with their hands on the table. What conclusion can be made about how they each will feel the vibrations?
Explanation:
that the people closer too the head of the table will feel more vibrations than the people at the end of the table. since the vibrations will slow down as they travel farther down the table
Hope this helps!!
PLEASE HELP ME
NEED IT FAST WILL GIVE B !! If correct
Answer:
25% :)
Explanation: