A 45 kg swimmer starting from rest can develop a maximum speed of 12 m/s over a distance of 20 m How much net force must be applied to do this ?

MUST SHOW WORK!

Answers

Answer 1

F = ma = mΔv/t = m(vf - vi)/t = mvf/t (since vi = 0)

⇒ a = vf/t


While accelerating from rest to vf, the distance d the swimmer traveled satisfies

d = (1/2)at2

Then

d = (1/2)(vf/t)t2 = vf t/2 ⇒

t = 2d/vf

F = ma = mvf/t = mvf / (2d/vf) = mvf2 / (2d)

F = [45 * 122 / (2 * 20)] N = 162 N

If you also want to know how long the swimmer took to accelerate to vf,

t = 2d/vf = (2 * 20 / 12) s = 3.33 s
Answer 2
55m got it right on edg

Related Questions

What equation would you use to solve for voltage?

Answers

Answer:

It depends upon what you have given in the question but according to Ohm's law,

[tex]\boxed{V\:= I × R}[/tex]

where, V = voltage (v)

I = current (amperes)

R = resistance (Ω)

Other formulas are:

V = P/IV = √P × R

Hope it helps!<3

PLEASE HELP! FOR BRAINLIEST!!!

Answers

Answer:

I think it's C I'm so sorry if I'm wrong.

Explanation:

Answer:

A or Alex > Chai > Jimmy > Sanni

Explanation:

__________________________________________________________

Here's why this is the answer,

__________________________________________________________

Alex's Range = 3.20 - 0.90 = 2.30

Sanni's Range = 1.35 - 1.30 = 0.05

Chai's Range = 2.10 - 1.05 = 1.05

Jimmy's Range = 2.20 - 1.55 = 0.65

__________________________________________________________

Greatest to Least

Alex > Chai > Jimmy > Sanni

Here's why this is correct.

Alex = 2.30

Chai = 1.05

Jimmy = 0.65

Sanni = 0.05

I do not see the answer I have on this question so I think it is A.

__________________________________________________________

Hope this helps! <3

__________________________________________________________

You bought a helium balloon for a friend’s winter birthday. The outside temperature was -34 degrees C. The store was at a comfortable 298K. The volume of the balloon immediately after the store clerk filled it was 6 liters. What was the volume after you brought it outside? Show your work. Make sure to include units.

Answers

Answer:

4.81 L

Explanation:

From the question given above, we obtained the following information:

Initial temperature (T₁) = 298 K

Initial Volume (V₁) = 6 L

Final Temperature (T₂) = – 34 °C

Final Volume (V₂) =?

Next, we shall convert – 34 °C to Kelvin temperature. This can be obtained as follow:

T(K) = T(°C) + 273

T(°C) = – 34 °C

T(K) = – 34 + 273

T(K) = 239 K

Thus, –34 °C is equivalent to 239 K

Finally, we shall determine the final volume of the balloon as follow:

Initial temperature (T₁) = 298 K

Initial Volume (V₁) = 6 L

Final Temperature (T₂) = 239 K

Final Volume (V₂) =?

V₁ / T₁ = V₂ / T₂

6 / 298 = V₂ / 239

Cross multiply

298 × V₂ = 6 × 239

298 × V₂ = 1434

Divide both side by 298

V₂ = 1434 / 298

V₂ = 4.81 L

Thus, the volume of the balloon when it was brought outside the store was 4.81 L.

Which of the following is a unit of acceleration?

Answers

[tex]{\tt{\red{\underline{\underline{\huge{Answer:}}}}}}[/tex]

[tex]\longrightarrow[/tex] The rate of change of velocity per unit time is called acceleration.

[tex]\longrightarrow[/tex] Its SI unit is m/s².

[tex]\huge\boxed{\fcolorbox{blue}{red}{Thank you}} [/tex]

An object has a force of 29.43 N acting on it. Its acceleration is 3.5 m/s2. What is the mass of this object?

Answers

Answer:

The mass of the object is 8.41 Kg.

Explanation:

Mechanical Force

The second Newton's law states that the net force exerted by an external agent on an object of mass m is:

F = m.a

Where a is the acceleration of the object. The SI unit for the force is the Newton: [tex]1\ Nw = 1~Kg.m/s^2[/tex]

We are given the net force of F=29.43 N acting on an object and producing an acceleration of a=3.5~m/s^2.

To calculate the mass of the object, we solve the above equation for m:

[tex]\displaystyle m=\frac{F}{a}[/tex]

[tex]\displaystyle m=\frac{29.43}{3.5}[/tex]

Calculating:

m = 8.41 Kg

The mass of the object is 8.41 Kg.

mass of the planet is 12 times that of earth and its radius is thrice that of earth , then find the escape velocity on that planet ?? ​

Answers

Answer:

The escape velocity on the planet is approximately 178.976 km/s

Explanation:

The escape velocity for Earth is therefore given as follows

The formula for escape velocity, [tex]v_e[/tex], for the planet is [tex]v_e = \sqrt{\dfrac{2 \cdot G \cdot m}{r} }[/tex]

Where;

[tex]v_e[/tex] = The escape velocity on the planet

G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²

m = The mass of the planet = 12 × The mass of Earth, [tex]M_E[/tex]

r = The radius of the planet = 3 × The radius of Earth, [tex]R_E[/tex]

The escape velocity for Earth, [tex]v_e_E[/tex], is therefore given as follows;

[tex]v_e_E = \sqrt{\dfrac{2 \cdot G \cdot M_E}{R_E} }[/tex]

[tex]\therefore v_e = \sqrt{\dfrac{2 \times G \times 12 \times M}{3 \times R} } = \sqrt{\dfrac{2 \times G \times 4 \times M}{R} } = 16 \times \sqrt{\dfrac{2 \times G \times M}{R} } = 16 \times v_e_E[/tex]

[tex]v_e[/tex] = 16 × [tex]v_e_E[/tex]

Given that the escape velocity for Earth, [tex]v_e_E[/tex] ≈ 11,186 m/s, we have;

The escape velocity on the planet = [tex]v_e[/tex] ≈ 16 × 11,186 ≈ 178976 m/s ≈ 178.976 km/s.

help pls its been a day

Answers

Answer:

161.28m

Explanation:

The resultant is calculated using the formula

R² = dx²+dy²

R = √dx²+dy²

From the diagram. dx = 101cos60°+85

dx = 101(0.5) + 65

dx = 50.5 + 85

dx = 135.5m

For the vertical component dy

dy = dsin theta

dy = 101 sin 60

dy = 101(0.8660)

dy = 87.47

R = √135.5²+87.47²

R = √18,360.25+7,651.0009

R = √26,011.2509

R = 161.28m

Hence the magnitude of the sum of the vectors is 161.28m

Answer:

The sum of the two vectors is 161.278 m.

Explanation:

Given;

vector, B = 101 m inclined at angle 60⁰

vector, A = 85 m inclined at angle 0⁰

Y-component of the vectors;

[tex]R_y = 101(sin \ 60^0) + 85(sin \ 0^0) =87.466 \ m[/tex]

X-component of the vectors;

[tex]R_x = 101(cos \ 60^0) + 85(cos \ 0^0)\\\\R_x = 50.5 + 85 = 135.5 \ m[/tex]

Sum of the two vectors;

[tex]R = A+ B\\\\R = \sqrt{R_y^2 + R_x^2} \\\\R = \sqrt{87.466^2 \ + \ 135.5^2} \\\\R = \sqrt{26010.55} \\\\R = 161.278 \ m[/tex]

Therefore, the sum of the two vectors is 161.278 m.

why watchman does no work but gets tired ?​

Answers

Answer: the body is trained to wake up when the sun rises and get the energy from the sun and sleep and it is night on when the sun is not there. So when a watchman works at night there is no sun first of all to give him any kind of energy and secondly the body clock resists him waking up thus making him tired.

Explanation:

Many things can alter your heart rate including: exercise, diet, nutrition, sugar, and caffeine

True or false

Answers

Answer:

true

Explanation:

a 10 kilogram steel ball is dropped from the top of a tower 100 meters high the kinetic energy of the ball just before it sttikes the ground is most nearly​

Answers

Explanation:

If we assume negligible air resistance and heat loss, we can assume that all of the Gravitational potential energy of the ball will turn into Kinetic energy as it falls toward the ground.

Therefore our Kinetic energy = mgh = (10kg)(9.81N/kg)(100m) = 9,810J.

- During a certain period, the angular position of a rotating object is given by: = − + , where  is in radian and t is in seconds. Determine the angular position, angular speed, and angular acceleration of the rotating object at = Sec.

Answers

The question is not complete. The complete question is :

During a certain period of time, the angular position of a rotating object is given by [tex]$\theta =2t^2 +10t+5$[/tex], where θ is in radians and t is in seconds.  Determine the angular position, angular speed, and angular acceleration of the door (a) at t = 0.00 seconds, (b) at t = 3.00 seconds.

Solution :

Given :

Displacement or angular position of the object, [tex]$\theta =2t^2 +10t+5$[/tex]

∴ Angular speed is   [tex]$\omega = \frac{d \theta}{dt}$[/tex]

                                 ω = 10 + 4t

And angular acceleration is [tex]$\alpha = \frac{d \omega}{dt}$[/tex]

                                              α = 4

a). At time, t = 0.00 seconds :

   Angular displacement is [tex]$\theta =2t^2 +10t+5$[/tex]

                                            [tex]$\theta =2(0)^2 +10(0)+5$[/tex]

                                               = 5 rad

  Angular speed is  ω = 10 + 4t

                                 ω = 10 + 4(0)

                                     = 10 rad/s

Angular acceleration is α = 4 [tex]$rad/s^2$[/tex]

b). At time, t = 3.00 seconds :

   Angular displacement is [tex]$\theta =2t^2 +10t+5$[/tex]

                                            [tex]$\theta =2(3)^2 +10(3)+5$[/tex]

                                               = 53 rad

  Angular speed is  ω = 10 + 4t

                                 ω = 10 + 4(3)

                                     = 22 rad/s

Angular acceleration is α = 4 [tex]$rad/s^2$[/tex]

                                   

                                           

A racecar is driving around a circular track. The car is moving with a speed of 49.7 m/s, and the track has a radius of 114 m. What is the magnitude of the centripetal acceleration of the car?

Answers

Answer:

21.67 m/s²

Explanation:

From the question given above, the following data were obtained:

Velocity (v) = 49.7 m/s

Radius (r) = 114 m

Centripetal acceleration (a) =?

The centripetal acceleration can be obtained by using the following formula:

a = v²/r

a = 49.7² / 114

a = 2470.09 / 114

a = 21.67 m/s²

Therefore, the centripetal acceleration of the car is 21.67 m/s²

in addition to genetics, and blank and blank may also cause premature gray hair?

Answers

Answer: heretidey and stress

Explanation:

show your work. john uses a 25N force to push a boulder off a cliff that is 312m tall. What is the work done on the boulder?​

Answers

Answer:7800

work=force x distance

Force in Newtons

Distance in Meters

Work in Joules

Question 8 of 15
Which of the following distinguishes electromagnetic waves from mechanical
waves?
A. They carry energy.
B. They have frequencies.
C. They have wavelengths.
D. They don't require a medium to travel through.


Answers

Answer:

D. They don't require a medium to travel through.

Explanation:

Electromagnetic waves and mechanical waves are both types of waves. Electromagnetic waves are waves that arise from the combination of electric and magnetic fields while mechanical waves are waves that arise as a result of transfer of energy via matter.

One major difference between these two types of waves is that electromagnetic waves such as light waves, radiowaves etc. do not need a medium to travel i.e. they can travel through a vacuum, while on the other hand, mechanical waves such as sound waves need a medium to travel.

Answer:

They don't require a medium to travel through

Explanation: hope this helps

How long will it take an object traveling at 7 m/s to reach a distance of 26 meters

Answers

Answer:

3 hours 71 minutes

Explanation:

As because Speed= distance/time taken

so time taken= 3.71

g. Write the merits and demerits of ultraviolet rays.

Answers

Answer:

UV rays aid in the production of Vitamin D. But it can also give you cancer.

Explanation:

i am a scientist

Why do you think it is colder during the winter than the summer?

Answers

Answer:

As the earth travels around the sun during the year it maintains this tilt. Because of this tilt, in the summer we (north of the equator) are slanted more directly towards the sun so it's hotter. In the winter, we're slanted away so the sun's rays are less direct, making it colder.

What is the height of a shelf that has 15 kg objects with 450 J of gravitational potential energy

Answers

PE=mgh
450J=15kg•9.8m/s2squared
450=147h
—— ——
147 147

h=3.0612m

A 10 kg object experiences an acceleration of 2 m/s squared. What net force was applied to the object?

Answers

F = ma

= 10kg × 2m/s

= 20N

Answer : 20N

Explanation :

F = Force (N)

m = mass (kg)

a = acceleration (m/s)

Which of the following situations is an example of kinetic energy being transformed into potential energy? Throwing a ball high into the air Dropping a ball from a ladder Rolling a ball on the ground Holding a ball in the air without moving it

Answers

Answer: holding the ball in the air without moving it

Explanation:

When the ball goes up it’s potential energy

Throwing a ball high into the air is an example of kinetic energy being transformed into potential energy.

What is kinetic energy ?

"Kinetic energy is a form of energy that an object or a particle has by reason of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and thereby gains kinetic energy."

What is potential energy ?

"Potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors."

Know more about potential energy here

https://brainly.com/question/24284560

#SPJ2

An object at rest has no net force acting on it.
True or False​

Answers

That’s True bc an unbalanced force would need to keep and object in motion at a constant velocity.

Answer:

True

Explanation:

The object is at rest, which means it's not moving, so there is no net force on it, according to Newton's First Law.

Using Velocity vs Time Graphs to Find Acceleration
A graph titled velocity versus time has horizontal axis time (seconds) and vertical axis velocity (meters per second). A line has 4 straight segments. Line segment A runs from 0 seconds 0 meters per second to 1 seconds 15 meters per second. Then segment B runs to 2 seconds 20 meters per second. Then segment C runs to 4 seconds 20 meters per second. Then segment D runs to 5 seconds 0 meters per second.

The acceleration of segment D is m/s2.



Rank segments A, B, and C from least acceleration to greatest acceleration.

Least:








Greatest:

Answers

The acceleration at segment D is -20m/s²

The rank of the acceleration from the least to the greatest is -20m/s² < 0m/s² < 5m/s² < 10m/s² (D<C<B<A)

Acceleration is the change in velocity with respect to time.

a = v-u/t

Acceleration at segment A:

Aa = 15-0/1-0

Aa = 15m/s²

Acceleration at segment B:

Ab = 20-15/2-1

Ab = 5m/s²

Acceleration at segment C:

Aa = 0-0/4-2

Aa = 0m/s²

Acceleration at segment D:

Ac = 0-20/5-4

Ac = -20m/s²

Hence the acceleration at segment D is -20m/s²

The rank of the acceleration from the least to the greatest is -20m/s² < 0m/s² < 5m/s² < 10m/s² (D<C<B<A)

Learn more here: https://brainly.com/question/18398656

Calculate the magnitude and direction of the centripetal acceleration of the following objects moving in a circle:

A 2000 kg truck drives along a circular round a bout with a radius of 20 m at a constant speed of 10 m/s.

Answers

Answer:

The magnitude and direction of the centripetal acceleration will be:

[tex]a_c=5[/tex] m/s²   (towards the center of the circle).

Explanation:

Given

v = 10 m/sr = 20 m

Using the formula to determine the centripetal acceleration

[tex]a_c=\frac{v^2}{r}[/tex]

[tex]a_c=\frac{\left(10\right)^2}{20}[/tex]

[tex]\:a_c=\frac{100}{20}[/tex]

[tex]a_c=5[/tex] m/s²

As the truck is moving in a circle, therefore the direction is towards the center of the circle.

Hence, the magnitude and direction of the centripetal acceleration will be:

[tex]a_c=5[/tex] m/s²   (towards the center of the circle).

(HELP PLEASE)What are some reasons people produce synthetic materials?

Answers

Answer:

Explanation:

Synthetic fabrics, such as nylon and polyester, are produced entirely from chemicals. Natural fabrics, such as cotton, silk, and wool are made of fibres from plants and animals. Synthetic fabrics are useful because they have very different or enhanced (improved) properties in comparison to natural materials.

A train travels with a speed of 115km/hr. How much time does it take to cover a distance of 470km.​

Answers

It would take approximately 4 hours for the train to cover a distance of 470km.

4 hours 5 minutes 13.04 seconds

A car with a mass of 900 kg is traveling at a
speed of 25 m/s. What is the kinetic energy
from the car's motion?

Answers

Explanation:

Kinetic Energy

= 0.5mv²

= 0.5(900kg)(25m/s)²

= 281,250J.

What is thermodynamics?
a) the way energy changes
b) the classification of energy
c) the movement of energy
d) the movement of heat

Answers

Answer:

I think it is D

Explanation:

Answer:

D :D lol

Explanation:

a ball bounce on the ground. at what position (A,B,C)does the ball have the greatest potential energy? kinetic energy? explain your answer.​

Answers

Answer:

What is the meaning of the kinetic I think the answer is both the ball has both Kinetic and potential energy so I think is the answer is true

A body moving in a straight line has a uniform motion if it travels ---------- distance in -------- intervals og time

Answers

Answer:

uniform an uniform

please fill it like yhis

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