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trapecia [35]
3 years ago
15

A machine has an efficiency of 70%. How much work dose the machine do when 20,000 J of work is done on it

Physics
1 answer:
hram777 [196]3 years ago
3 0
If the machine works at a 70% efficiency it must complete 14,000 work out of the 20,000
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An airplane flies with a constant speed of 800km/h. How far can it travel in 2 hours?
Nataly [62]
Because the airplane flies at 800 km/h, it will fly 800 km in 1 hour.  In order to find how far it travels in 2 hours, we multiply this number by 2.  800*2 = 1600, so the plane will travel 1600 km in 2 hours.
5 0
3 years ago
An object of mass 2.0 kg is attached to the top of a vertical spring that is anchored to the floor. The unstressed length of the
poizon [28]

Answer:

The value is A  =  0.014 \  m

Explanation:

From the question we are told that

    The mass of the object is  m  =  2.0 \  kg

    The unstressed length of the string is  l  =  0.08 \  m

    The length of the spring when it is  at equilibrium is  l_e = 5.9 \  cm  =  0.059 \  m

      The initial speed (maximum speed)of the spring when given a downward blow v  =  0.30 \  m/s

Generally the maximum speed  of the spring  is mathematically represented as

           u =  A *  w

Here A is maximum height above the floor (i.e the maximum amplitude)

            and w is the angular frequency which is mathematically represented as

       w = \sqrt{\frac{k}{m} }

So

        u =  A *   \sqrt{\frac{k}{m} }

=>      A  =  u *   \sqrt{\frac{m}{k} }

Gnerally the length of the compression(Here an assumption that the spring was compressed to the ground by the hammer is made) by the hammer is mathematically represented as

           b  =  l -l_e

=>         b  = 0.08 - 0.05 9

=>         b  = 0.021 \  m

Generally at equilibrium position the net force acting on the spring is  

            k *  b  -  mg  =  0

=>         k *  0.021   -   2 * 9.8  =  0

=>        k =  933 \  N/m

So

            A  =  0.30  *   \sqrt{\frac{2}{933} }

=>          A  =  0.014 \  m

8 0
3 years ago
Two cars are initially separated by 2500 m and traveling towards each other. One car travels at 4.5 m/s and the second car trave
mylen [45]

Answer:

714.285s

Explanation:

use relative velocity

8-4.5 = 3.5m/s

x = 2500m

2500/3.5 = 714.285s = 700s (with sig figs)

7 0
3 years ago
What two types of evidence are used to classify orgianisms?
jeyben [28]
One is their traits and their characterists that they have in common 
6 0
3 years ago
Read 2 more answers
On the kelvin scale what is the freezing point of water
Alla [95]
Freezing point of the water is known as 273 K

Hope this helps!
8 0
3 years ago
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