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If a ball has the weight of 3.76, how much work would it take to lift it 2 meters above the ground? (sorry if this question does

Aloiza [94]

We know, work done = Weight * Displacement
w = 3.76 * 2
w = 7.52 J

In short, Your Answer would be: 7.52 Joules

Hope this helps!

7 0

2 years ago

The power of a lens is 4. 0 diopters and its diameter is 5. 0 cm. what is the focal length of this lens?

fenix001 [56]

The focal length of the lens is 25cm

given:

power,p=4 diopters

what is focal length?

Focal length is the distance between the point of convergence of your lens and the sensor or film recording the image.

what is diopter?

The unit of optical power of lens is called diopter.It is the optical power of the lens.

we know,

p=1/f

where,

p= power

f= focal length

f=1/p

f=1/4

=0.25m

=25cm

Thus,the focal length of the lens is 25cm

learn more about focal length from here: https/brainly.com/question/28203589

#SPJ4

8 0

2 years ago

Explain why it is esaier to climb a mountain on a zigzag path rather than one straight up the side. is your increase in gravitat

pogonyaev

Answer:

More work done with less power

The increase in gravitational energy is the same as the height which is a function of gravitational energy is the same in both cases

Explanation:

Climbing the mountain in zigzag pattern is easier because

1. The time it takes to climb increases so that the required power or rate of doing work decreases

2. Climbing in zigzag pattern affords the use of leverages by the sides

3. Similar mechanical power gain and efficiency from using a drive screw instead of a nail to fasten items together can be achieved

The increase in gravitational energy is the same gravitational energy ~ mass × gravity ×height

6 0

3 years ago

A satellite orbits earth with a mean altitude of 361 km. If the orbit is circular, what are the satellite's time period and spee

Advocard [28]

Answer:

v = 7.69 x 10³ m/s = 7690 m/s

T = 5500 s = 91.67 min = 1.53 h

Explanation:

In order for the satellite to orbit the earth, the force of gravitation on satellite must be equal to the centripetal force acting on it:

$F_{gravitation}= F_{centripetal}\\\\\frac{GM_{s} M_{E}}{r^2} = \frac{M_{s} v^2}{r}\\\\\frac{GM_{E}}{r} = v^2\\\\v = \sqrt{\frac{GM_{E}}{r} } \\\\$

where,

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

Me = Mass of Earth = 5.97 x 10²⁴ kg

r = distance between the center of Earth and Satellite = Radius of Earth + Altitude = 6.371 x 10⁶ m + 0.361 x 10⁶ m = 6.732 x 10⁶ m

v = orbital speed = ?

Therefore,

$v = \sqrt{\frac{(6.67 x 10^{-11}N.m^2/kg^2)(5.97 x 10^{24} kg)}{6.732 x 10^6 m} }\\\\$

For time period satellite completes one revolution around the earth. It means that the distance covered by satellite is equal to circumference of circle at the given altitude.

So, its orbital speed can be given as:

$v = \frac{Circumference of Circle at Given Altitude}{T}\\\\v = \frac{2\pi r}{T}\\\\$

where,

T = Time Period of Satellite = ?

Therefore,

$T = \frac{2\pi r}{v}\\\\T = \frac{(2\pi )(6.732 x 10^6 m}{7.69 x 10^3 m/s}\\\\$

7 0

3 years ago

An electric pump rated 1.5 KW lifts 200kg of water through a vertical height of 6m in 10 secs: way is the efficiency of the pump

ruslelena [56]

Answer:

80%

Explanation:

Efficiency = Power output / Power input × 100 %

To calculate efficiency we need to find power output of electric pump.

We can use,

Work done = Energy change

Work done per second = Energy change per second

Work done per second = Power

Therefore, Power = Energy change per second

= Change in potential energy of water per second

=mgh / t

= 200× 10×6 / 10

= 1200 W = 1.2 kW

Now use the first equation to find efficiency,

Efficiency = $\frac{1.2}{1.5}$ × 100%

= 80 %

8 0

3 years ago