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3 years ago

A book weighing 2.0 Newtons is lifted 3.0 meters in 4.0 seconds. How much work was done? SHOW WORK

Physics

1 answer:

qaws [65]3 years ago

7 0

6 Ns is the work done on the book to lift it by 3 m.

Answer:

Explanation:

Work done is the measure of amount of force required to move an object from its initial position to any desired position. So mathematically it can be calculated as the product of force acting on that object to the displacement of that object. Thus, work done on any object or by any object is directly proportional to the force acting on that object and the displacement of that object.

Work done = Force × displacement

As here the force is said to be 2 N and the displacement of the book is said to be 3 m, the work done on the book is

Work done = 2×3 = 6 N.s.

The time has no role to do on the work done calculation to be performed on the object.

Thus, 6 Ns is the work done on the book to lift it by 3 m.

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What is one benefit of lifelong physical activity?

kvasek [131]

The answer would be C

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3 years ago

I need homework help

KIM [24]

1) the weight of an object at Earth's surface is given by $F=mg$ , where m is the mass of the object and $g=9.81 m/s^2$ is the gravitational acceleration at Earth's surface. The book in this problem has a mass of m=2.2 kg, therefore its weight is
$F=mg=(2.2 kg)(9.81 m/s^2)=21.6 N$

2) On Mars, the value of the gravitational acceleration is different: $g=3.7 m/s^2$ . The formula to calculate the weight of the object on Mars is still the same, but we have to use this value of g instead of the one on Earth: $F=mg=(2.2 kg)(3.7 m/s^2)=8.1 N$

3) The weight of the textbook on Venus is F=19.6 N. We already know its mass (m=2.2 kg), therefore by re-arranging the usual equation F=mg, we can find the value of the gravitational acceleration g on Venus:
$g= \frac{F}{m}= \frac{ 19.6 N}{2.2 kg}=8.9 m/s^2$

4) The mass of the pair of running shoes is m=0.5 kg. Their weight is F=11.55 N, therefore we can find the value of the gravitational acceleration g on Jupiter by re-arranging the usual equation F=mg:
$g= \frac{F}{m} = \frac{11.55 N}{0.5 kg} =23.1 m/s^2$

5) The weight of the pair of shoes of m=0.5 kg on Pluto is F=0.3 N. As in the previous step, we can calculate the strength of the gravity g on Pluto as
$g= \frac{F}{m} = \frac{0.3 N}{0.5 kg} =0.6 m/s^2$

6) On Earth, the gravity acceleration is $g=9.81 m/s^2$ . The mass of the pair of shoes is m=0.5 kg, therefore their weight on Earth is
 $F=mg=(0.5 kg)(9.81 m/s^2)=4.9 N$

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3 years ago

Calculate the heat, in kilocalories, that is absorbed if 183 g of ice at 0.0 ∘C is placed in an ice bag, melts, and warms to bod

boyakko [2]

Answer:

The total amount of heat needed will be $Q_T=21.411kcal$ .

Explanation:

We will divide the calculation in two: First, the heat needed to melt the ice, and then the heat needed to warm the resulting liquid from 0°C to 37°C.

$m=183g$

$l_f=80\frac{cal}{g} =334\frac{J}{g}$

$l_w=1\frac{cal}{g} =4.184\frac{J}{g}$

i) The fusion heat will be:

$Q_f=l_fm=14640cal=14.640kcal$

ii) The heat needed to warm the water from $T_i=0^{\circ}C$ to $T_i=37^{\circ}C$ will be:

$Q_w=l_wm(T_f-T_i)=6771cal=6.771kcal$

So, the total amount needed will be the sum of these two results:

$Q_T=Q_f+Q_w=14.640kcal+6.771kcal=21.411kcal$ .

8 0

3 years ago

A person is pulling a freight cart with a force of 58 pounds. how much work is done in moving the cart 70 feet if the cart's han

Kobotan [32]

The person is dragging with a force of 58 lbs at an angle of 27 degrees relating to the ground. We want to use cosine function to look for the horizontal force component. And then we can compute for W = (Horizontal Force) x (Distance). We want the horizontal force component since that is the component that is parallel to the direction the cart is moving. 

(cos 27 degrees)(58 lbs) = 51.69 lbs (This is the horizontal force component.)
W = (51.69 lbs) x (70 ft) = 3618.3 ft*lbs

6 0

3 years ago

A wave traveling in water has a frequency of 500.0 Hz and a wavelength of 3.00 m. What is the speed of the wave?

Sergeu [11.5K]

Answer:

1500 m/s

Explanation:

Recall that for a wave,

Speed = frequency x wavelength

here we are given frequency = 500 Hz and wavelength = 3m

simply substitute into above equation

Speed = 500 Hz x 3m

= 1500 m/s

6 0

3 years ago