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Nat2105 [25]
2 years ago
9

Find the efficiency of a machine that does 800 J of work if the input work is 2,000 J.

Physics
1 answer:
torisob [31]2 years ago
3 0

Answer:

Efficiency: 0.4 (40%)

Explanation:

The efficiency of a simple machine is given by the ratio

\eta = \frac{W_{out}}{W_{in}}

where

W_{in} is the input work of the machine

W_{out} is the output work of the machine

For the machine in this problem, we have:

W_{out}=800 J is the output work

W_{in}=2000 J is the input work

Therefore, the efficiency of the machine is

\eta=\frac{800}{2000}=0.4

Which can be also written as percentage:

\eta=0.4\cdot 100 = 40\%

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Kevin Tan's Balance Sheet. Total assets are 13,200 dollars. Total liabilities are 9,150 dollars. What is Kevin’s net worth on Ma
Alexus [3.1K]

Answer:

4,050

Explanation:

I did the math.

5 0
2 years ago
A Labrador retriever breeder needs to determine if three male pups who were born to Sadie, his black Labrador retriever, are the
Novosadov [1.4K]

Answer: The things we know are:

Sadie, the mother, is a black labrador.

Sam, the possible father, is a yellow labrador.

Discarding things such as a scientific indagation, the breeder could look for traits in the pups.

For example, yellow is recessive against black, so if the pups are yellow, there is probable that the father is Sam, none the less, if the pups are black there is also the possibility where Sam is the father, just in this case the color genes that the pups received are the ones of the mother.

A good starting point is looking at the color, the posture, and things like that.

In the end, these things are only statistics, there is not any determination here, the only real (scientific) determinative process is a paternity test.

7 0
2 years ago
The wavelength of green light is 550 nm.
SIZIF [17.4K]

Answer:

(a) momentum of photon is 1.205 x 10⁻²⁷ kgm/s

    velocity of electron is 1323.88 m/s

   momentum of the electron is 1.205 x 10⁻²⁷ kgm/s

(b) momentum of photon is 1.506 x 10⁻²⁷ kgm/s

  velocity of electron is 1654.85 m/s

  momentum of the electron is 1.506 x 10⁻²⁷ kgm/s

(c) The momentum of the photon is equal to the momentum of the electron

Explanation:

(a)

wavelength of green light, λ = 550 nm

momentum of photon is given by;

p = \frac{h}{\lambda}\\\\ p = \frac{6.626 *10^{-34}}{550*10^{-9}}\\\\p = 1.205 *10^{-27} \ kg.m/s

velocity of electron is given by;

P = \frac{h}{\lambda} \\\\mv = \frac{h}{\lambda}\\\\v = \frac{h}{m \lambda}\\\\v =   \frac{6.626 *10^{-34}}{(9.1*10^{-31} )(550*10^{-9})}\\\\v = 1323.88 \ m/s

momentum of the electron is given by;

p = mv

p = (9.1 x 10⁻³¹) (1323.88)

p = 1.205 x 10⁻²⁷ kgm/s

(b)

wavelength of red light, λ = 440 nm

momentum of photon is given by;

p = \frac{h}{\lambda}\\\\ p = \frac{6.626 *10^{-34}}{440*10^{-9}}\\\\p = 1.506 *10^{-27} \ kg.m/s

velocity of electron is given by;

v =   \frac{6.626 *10^{-34}}{(9.1*10^{-31} )(440*10^{-9})}\\\\v = 1654.85 \ m/s

momentum of the electron is given by;

p = mv

p =  (9.1 x 10⁻³¹) (1654.85)

p = 1.506 x 10⁻²⁷ kgm/s

(c) The momentum of the photon is equal to the momentum of the electron.

7 0
2 years ago
A plane flying at 70.0 m/s suddenly stalls. If the acceleration during the stall is 9.8 m/s2 directly downward, the stall lasts
tino4ka555 [31]

Answer:

v = 66.4 m/s

Explanation:

As we know that plane is moving initially at speed of

v = 70 m/s

now we have

v_x = 70 cos25

v_x = 63.44 m/s

v_y = 70 sin25

v_y = 29.6 m/s

now in Y direction we can use kinematics

v_y = v_i + at

v_y = 29.6 - (9.81 \times 5)

v_y = -19.5 m/s

since there is no acceleration in x direction so here in x direction velocity remains the same

so we will have

v = \sqrt{v_x^2 + v_y^2}

v = \sqrt{63.44^2 + 19.5^2}

v = 66.4 m/s

4 0
2 years ago
A meter stick balances at the 50.0-cm mark. If a mass of 50.0 g is placed at the 90.0-cm mark, the stick balances at the 61.3-cm
Airida [17]

Answer:

126.99115 g

Explanation:

50 g at 90 cm

Stick balances at 61.3 cm

x = Distance of the third 0.6 kg mass

Meter stick hanging at 50 cm

Torque about the support point is given by (torque is conserved)

mgl_1=Mgl_2\\\Rightarrow M=\dfrac{ml_1}{l_2}\\\Rightarrow M=\dfrac{50\times (61.3-90)}{50-61.3}\\\Rightarrow M=126.99115\ g

The mass of the meter stick is 126.99115 g

6 0
2 years ago
Read 2 more answers
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