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IceJOKER [234]
3 years ago
11

A cargo elevator on Earth (where g = 10 m/s2) lifts 3000 kg upwards by 20 m. 720 kJ of electrical energy is used up in the proce

ss. What is the efficiency of this process?
Physics
1 answer:
MakcuM [25]3 years ago
8 0

Answer: 83%

Explanation:

Efficiency of the process = work output/work input × 100%

Work input is the energy used up in the process = 720,000Joules

Work output = Force × distance

= (3000×10)× 20

= 600000 Joules

Efficiency= 600000/720000 × 100

= 0.83×100

= 83%

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A boat is rowed perpendicular to the shore of a river that flows at 3.0 m/s as shown in the
vazorg [7]
The magnitude is 5 ms^-1

6 0
2 years ago
A planet has been observed orbiting a nearby star. This star has a mass of 3.5 solar masses, and the planet is 4.2 AU from the s
kondaur [170]

Answer:

4.6 years

Explanation:

This is solved using Kepler's third law which says:

T^2=\frac{4\pi ^2}{GM} a^2

Where

T = Orbital period of the planet (in seconds)

a = Distance from the star (in meters)

G = Gravitational constant

M = Mass of the parent star (in kg)

From the information given

M = 3.5M_{sun} = 6.96*10^{30} kg

a=4.2AU = 6.28*10^{11} meters

G = 6.67*10^{-11}m^3kg^{-1}s^{-2}

We put this into Kepler's law and get:

T=\sqrt{\frac{4\pi ^2}{6.67*10^{-11}*6.96*10^{30}} (6.28*10^{11})^3}=145,128,196 seconds.

This when converted to years is 4.6 years.

4 1
2 years ago
Read 4 more answers
Identify the formula for the binary ionic compound, aluminum oxide.​
vesna_86 [32]

Answer:

my bad ion even know what it is i just need sum points

Explanation:

3 0
3 years ago
Read 2 more answers
5. A family of ducks is swimming in a pond at a speed of 3 m/s when a gust of wind hits them. By the time they reach the other s
ella [17]

Answer:

The time taken by the duck to cross the lake is, t= 4 s

Explanation:

Given data,

The initial speed of the ducks, u = 3 m/s

The final speed of the ducks, v = 7 m/s

The acceleration of the duck, a = 1 m/s²

The formula for the acceleration is,

                               a = (v - u) / t

∴                               t = (v - u) / a

Substituting the given values in the above equation,

                                t = (7 - 3) / 1

                                  = 4 s

Hence, the time taken by the duck to cross the lake is, t= 4 s

6 0
3 years ago
Interest groups representing businesses and investors are often among the most successful lobbying groups in foreign policy. Why
alisha [4.7K]

The members of these groups make up the majority of voters in many districts thus this  be considered a problem.

<u>Option: D</u>

<u>Explanation:</u>

Interest groups play a key role in US politics. Such organizations are made up of wealthy and powerful members who often seek to impose some form of leverage in politicians to promote their goals and agendas. Across the years via many campaigns, they have understood how to speak and manipulate elected leaders and apply leverage to get the kind of legislation that is in their favor. Here the majority of voters in several districts are standing due to group members, as we recognize the interest group belongs to a body in which it uses different methods of lobbying to influence others.

7 0
3 years ago
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