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astra-53 [7]
3 years ago
7

A watermelon is thrown down from a skyscraper with a speed of 7.0 m/s. It lands with an impact velocity of 20 m/s. We can ignore

air resistance. What is the displacement of the watermelon?
Physics
2 answers:
Ivenika [448]3 years ago
8 0

Answer:

17.89 m/s

Explanation:

recall that one of the equations of motion can be expressed as:

v² = u² + 2as,

where

v = final velocity = given as 20 m/s

u = initial velocity = given as 7.0 m/s

a = acceleration. Since it is freefalling downwards, the acceleration it would experience would be the acceleration due to gravity = 9.81 m/s²

s = displacement (we are asked to find)

simply substitute the known values into the equation:

v² = u² + 2as

20² = 7² + 2(9.81)s

400 - 49 = 19.62s

19.62s = 351

s = 351/19.62

s = 17.8899

s = 17.89 m/s

Volgvan3 years ago
8 0

Answer:

It’s actually -18

Explanation:

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Vlada [557]

The two tests used for measuring each of the following fitness areas are as follows:

     a) Cardiorespiratory fitness → The 2.4 km run test; Astrand treadmill test

     b) Muscle strength → Muscle Testing Scale,  Bench/Leg press

     c) Body Composition → DEXA Scan, Bioelectrical Impedance Analysis

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      Cardiorespiratory fitness is a vital indicator of both physical and mental wellbeing. It can lower the chance of developing heart disease and type 2 diabetes. Cardiorespiratory fitness improves lung and heart health while also increasing emotions of well-being.

  • The astrand treadmill test is used widely for testing the fitness of cardiorespiratory. The usefulness of this test is used to assess a client's aerobic fitness.
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      Muscle strength refers to the capacity to move and lift items.  It is determined by the amount of power you can exert and the amount of weight you can lift within a short amount of time.

   

      The test used to determine the muscle strength can be:

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     Muscular strength testing is used to examine a complaint of weakness, which is common when there is a suspectable neurologic illness or muscle imbalance.

 

      Bench presses are weight-training exercises that can be added to your routine to help increase upper body strength and improve muscular endurance.

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       The test used to determine the body Composition can be:

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brainly.com/question/10033432?referrer=searchResults

       

8 0
2 years ago
One particular descent goes from 2100m to 1600m. Assuming work done against friction is 90% of the potential energy change of th
alisha [4.7K]

Answer:

1/2 M V^2 = .1 M g H       where 10% of PE goes into KE

V^2 = .2 g H = .2 * 9.8 * (2100 - 1600) = 980 m^2 / s^2

V = 31.1 m/s       increase in speed during descent

1 km / hr = 1000 m / 3600 sec = .278 m/s

V = 31.1 m/s / (.278 m/s / km /hr)= 112 km/hr

7 0
1 year ago
Which of the following describes the relationship between the weight of fluid
ioda
The answer is archimedes principle
8 0
2 years ago
A beam of unpolarized light with intensity I0 falls first upon a polarizer with transmission axis θTA,1 then upon a second polar
loris [4]

Answer:

The intensity I₂ of the light beam emerging from the second polarizer is zero.

Explanation:

Given:

Intensity of first polarizer = Io/2

For the second polarizer, the intensity is equal:

I_{2} =\frac{I_{o} }{2} (cos\theta )^{2} =\frac{I_{o} }{2} (cos90)^{2} =0

5 0
3 years ago
Calculate the electrical energy use of the microwave in 120 V circuit has 7.5 A current flow, if it used for 0.05 hours
Elden [556K]

Answer:

162 KJ

Explanation:

The electrical energy can be calculated using the formula

E = V×I×t

Where, V= voltage = 120 V

I is current in ampere = 7.5 A and t is time in seconds

1 hour = 3600 sec

Therefore, 0.05 hour = 3600×0.05 = 180 sec

Substitute the values in above equation find electrical power

E = 120×7.5×180

= 162000 J

= 162 KJ

Therefore, the electrical energy use of the microwave = 162 KJ

3 0
2 years ago
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