1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Anon25 [30]
3 years ago
7

Brutus, a champion weight lifter, raises 220 kg a distance of 3.10 m. (a) how much work is done by brutus lifting the weights? j

(b) how much work is done holding the weights above his head? j (c) how much work is done lowering them back to the ground? j(d) does brutus do work if the weights are let go and fall back to the ground? no yes (e) if brutus completes the lift in 2.1 s, how much power is developed? w
Physics
1 answer:
Nana76 [90]3 years ago
3 0
A) work = force * distance 
mass is not a force, weight is, so we have to find the weight of the block. 
Weight = mg 
Weight = (220kg)(9.8) 
Weight = 2156N 
Work = 2156N * 3.10m 
work = 6683.6J 
b) Since he is holding the weights, it's not moving, therefore, he doesn't do any work 
c) The answer is still the same amount of work when he lifted them. 
d) The answer is no since when he let go the weight, he doesn't apply any force to the weight. 
e) P = work/time 
P = 6683.6J / 2.1s 
P = 3182.67 watts 
You might be interested in
A ray of light passes from one material into a material with a higher index of refraction. Determine whether each of the followi
nikitadnepr [17]

Answer:

a) the Angle te also decreases , b) decrease, c) unchanged , d) the speed decrease , e) unchanged

Explanation:

When a ray of light passes from one transparent material to another, it must comply with the law of refraction

     n1 sin θ₁ = n2 sin θ₂

Where index v1 is for the incident ray and index 2 for the refracted ray

With this expression let's examine the questions

a) They indicate that the refractive index increases,

      sin θ₂ = n₁ / n₂ sin θ₁

     θ₂ = sin⁻¹ (n₁ /n₂   sin θ₁)

    As m is greater than n1 the quantity on the right is less than one, the whole quantity in parentheses decreases so the Angle te also decreases

Answer is decrease

b) The wave velocity eta related to the wavelength and frequency

      v = λ f

The frequency does not change since the passage from one medium to the other is a process of forced oscillation, resonance whereby the frequency in the two mediums is the same.

The speed decreases with the indicated refraction increases and therefore the wavelength decreases

      λ = λ₀ / n

The answer is decrease

c) from the previous analysis the frequency remains unchanged

d) the refractive index is defined by

       n = c / v

So if n increases, the speed must decrease

The answer is decrease

e) the energy of the photon is given by the Planck equation

      E = h f

Since the frequency does not change, the energy does not change either

Answer remains unchanged

7 0
3 years ago
ASAP
KatRina [158]

Answer:

<h3>The answer is 11 mL</h3>

Explanation:

To find the volume of the object we use the formula

volume of object = final volume of water - initial volume of water

From the question

final volume of water = 86 mL

initial volume of water = 75 mL

So we have

volume of object = 86 - 75

We have the final answer as

<h3>11 mL</h3>

Hope this helps you

4 0
3 years ago
A piston-cylinder device initially contains 0.6 kg of water with a volume of 0.1 m3 . The mass of the piston is such that it mai
Sloan [31]

Answer: Hello the missing piece of your question is attached

question : Determine mass of steam that has entered ( in kg )

answer : 0.206 kg

Explanation:

V1 = 0.1 m^3 ,

v' = V1 / m1 = 0.1 / 0.6 = 0.167 m^3/kg

V2 = 0.2 m^3

using the steam tables

at ; P = 1000 kPa, v' = 0.167 m^3/kg

U1 = 2321  KJ/kg

at ; P = 1000 kPa , T2 = 280°C

v'2= 0.2481 m^3kg

U2 = 2760.6

at ; P = 5MPa ,  T = 500°C

h1 = 3434.7 KJ/Kg

calculate final mass ( m2 )

M2 = V2 / v'2

      = 0.2 / 0.2481 =  0.806 kg

therefore the mass added =  m2 - m1

                                            = 0.806 - 0.6 =  0.206 kg

3 0
3 years ago
As shown in the figure below, a seal and the penguin are playing a fun game of tag. The penguin first swims rightward
RSB [31]

Answer:

Explanation:

Average velocity = Displacement/Time

ΔS = -10+6

ΔS = -4m

Given tme = 30s

Average velocity = -4/30

Average velocity = -0.13m/s

Average speed = Distance/Time

Total distance covered = 10m+6m

Total distance covered = 16m

Average speed = 16/30

Average speed = 0.53m/s

7 0
3 years ago
Earth is 149.6 million meters from the Sun and takes 365 days to make one complete revolution around the Sun. Mars is 227.9 mill
luda_lava [24]

Answer:

\frac{a_{r,earth}}{a_{r,mars}} = 2.325

Explanation:

The distance of Earth from the Sun is 149.6\times 10^{9}\,m and of Mars from the Sun is 227.9\times 10^{9}\,m. Let assume that both planets have circular orbits. The centripetal accelaration can be found by using the following expression:

a_{r} = \frac{v^{2}}{R}

Since planet has translation at constant speed, this formula is applied to compute corresponding speeds:

v=\frac{2\pi\cdot r}{\Delta t}

Earth:

v_{earth} = \frac{2\pi\cdot (149.6\times 10^{9}\,m)}{(365\,days)\cdot(\frac{24\,hours}{1\,day} )\cdot(\frac{3600\,s}{1\,h} )}

v_{earth}=29806.079\,\frac{m}{s}

Mars:

v_{mars} = \frac{2\pi\cdot (227.9\times 10^{9}\,m)}{(687\,days)\cdot(\frac{24\,hours}{1\,day} )\cdot(\frac{3600\,s}{1\,h} )}

v_{mars}=24124.244\,\frac{m}{s}

Now, centripetal accelarations can be found:

Earth:

a_{r,earth} = \frac{(29806.079\,\frac{m}{s} )^{2}}{149.6\times 10^{9}\,m}

a_{r,earth} = 5.939\times 10^{-3}\,\frac{m}{s^{2}}

Mars:

a_{r,mars} = \frac{(24124.244\,\frac{m}{s} )^{2}}{227.9\times 10^{9}\,m}

a_{r,mars} = 2.554\times 10^{-3}\,\frac{m}{s^{2}}

The ratio of Earth's centripetal acceleration to Mars's centripetal acceleration is:

\frac{a_{r,earth}}{a_{r,mars}} = \frac{5.939}{2.554}

\frac{a_{r,earth}}{a_{r,mars}} = 2.325

7 0
3 years ago
Other questions:
  • Which of the following molecules is correctly paired with its macromolecule class? (2 points)
    8·1 answer
  • What force stops a car from sinking into the road surface?
    5·2 answers
  • After a laser bean passes through two thin parallel slits, thefirst completely dark fringes occur at ± 15.00with the original di
    8·1 answer
  • A 55-kg skier starts from rest at the top of a ski jump, point A in Fig. 6–48, and travels down the ramp. If fric- tion and air
    14·2 answers
  • Determine qual é a carga elétrica de um corpo que possui 1 milhão de partículas?
    13·1 answer
  • You push a 45 kg wooden box across a wooden floor at a constant speed of 1.0 m/s. The coefficient of kinetic friction is 0.25. N
    12·1 answer
  • A completely inelastic collision occurs between two balls of wet putty that move directly toward each other along a vertical axi
    9·1 answer
  • Savvas realize hot on the inside
    11·2 answers
  • Forces are _______________ quantities since they have magnitude and direction.
    13·1 answer
  • Which variables are involved in understanding Kepler's third law of motion? (1 point)
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!