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2 years ago

99 POINTS PLEASE HELP

Physics

2 answers:

Ipatiy [6.2K]2 years ago

6 0

The answer is C.) Work

Force is not a quantity of the transfer of energy. An example of force would be when you push on a wall. You are applying force on a wall but the wall doesn't move. Thus, there is no transfer of energy.

The SI unit for force is Newtons (N)

Motion is a representation of force, not a quantity of the transfer of energy. When you see a ball rolling on the ground, this is because something pushed it and applied force, or the force of gravity is pulling down on it. There is also no transfer of energy in motion.

The SI unit for motion is Meters Per Second (m/s)

Work is the quantity of the transfer of energy. If you were to push on a door and it opens, energy has been transferred from your arms to the door; thus, there is work present.

The SI unit for work is a Watt (W), or Joules per Second (j/s)

Let me know if you need any clarifications, thanks!

~ Padoru

yarga [219]2 years ago

3 0

the answer to your problem is work

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So far in your life, you may have assumed that as you are sitting in your chair right now, you are not accelerating. However, th

tia_tia [17]

Answer:

a) $a=33.73mm/s^{2}$

b) mg>N

c) $\%_{change}=0.343\%$

d) $a=24.07mm/s^{2}$

Explanation:

In order to solve part a) of the problem, we can start by drawing a free body diagram of the presented situation. (see attached picture).

In this case, we know the centripetal acceleration is given by the following formula:

$a_{c}=\omega ^{2}r$

where:

$\omega=\frac{2\pi}{T}$

we know the period of rotation of the earth is about 24 hours, so:

$T=24hr*\frac{3600s}{1hr}=86400s$

so we can now find the angular speed:

$\omega=\frac{2\pi}{86400s}$

$\omega=72.72x10^{-6} rad/s^{2}$

So the centripetal acceleration will be:

$a_{c} =(72.72x10^{-6} rad/s^{2})^{2}(6478x10^{3}m)$

which yields:

$a_{c}=33.73mm/s^{2}$

In order to answer part b, we must draw a free body diagram of us sitting on a chair. (See attached picture.)

So we can do a sum of forces in equilibrium:

$\sum F=0$

so we get that:

$N-mg+ma_{c} = 0$

and solve for the normal force:

$N=mg-ma_{c}$

In this case, we can clearly see that:

$mg>mg-ma_{c}$

therefore mg>N

This is because the centripetal acceleration is pulling us upwards, that will make the magnitude of the normal force smaller than the product of the mass times the acceleration of gravity.

So let's calculate our weight and normal force:

Let's say we weight a total of 60kg, so:

$mg=(60kg)(9.81m/s^{2})=588.6N$

and let's calculate the normal force:

$N=m(g-a_{c})$

$N=(60kg)(9.81m/s^{2}-33.73x10^{-3}m/s^{2})$

N=586.58N

so now we can calculate the percentage change:

$\%_{change} = \frac{mg-N}{mg}x100\%$

so we get:

$\%_{change} = \frac{588.6N-586.58N}{588.6N} x 100\%$

$\%_{change}=0.343\%$

which is a really small change.

d) In order to find this acceleration, we need to start by calculating the radius of rotation at that point of earth. (See attached picture).

There, we can see that the radius can be found by using the cos function:

$cos \theta = \frac{AS}{h}$

In this case:

$cos \theta = \frac{r}{R_{E}}$

so we can solve for r, so we get:

$r= R_{E}cos \theta$

in this case we'll use the average radius of earch which is 6,371 km, so we get:

$r = (6371x10^{3}m)cos (44.4^{o})$

which yields:

r=4,551.91 km

and now we can calculate the acceleration at that point:

$a=\omega ^{2}r$

$a=(72.72x10^{-6} rad/s)^{2}(4,551.91x10^{3}m$

$a=24.07 mm/s^{2}$

5 0

2 years ago

Select the correct answer what is meditation

german

Answer:

Meditation can be defined as a set of techniques that are intended to encourage a heightened state of awareness and focused attention. Meditation is also a consciousness-changing technique that has been shown to have a wide number of benefits on psychological well-being.

3 0

2 years ago

A tow truck drags a stalled car along a road. The chain makes an angle of 30???? with the road and the tension in the chain is 1

My name is Ann [436]

Answer: work = 1,305kJ

Explanation:

angle= 30°

force= 1,500N

distance= 1,000m

The formula for work is : Work= force x distance, however there is an angle of 30° between the direction of force applied and the direction of motion, therefore force must be decomposed to its value on the horizontal axis which is the direction of motion by using the cosine of the very angle.

W= F×cos(α)×D

W= 1,500×cos (30)×1,000

W= 1,305kJ ( kilojoules)

3 0

3 years ago

The largest building in the world by volume is the Boeing 747 plant in Everett, Washington. It measures approximately 634 m long

Mazyrski [523]

So to get the volume, you're going to multiply all three together, but you have to make all the units the same first. The answer wants ft³, so you want to convert them all to feet. height = 109 ft, so that's fine already. Awesome. width = 710 yd, but that's an easy conversion to feet. Three feet equal one yard, so just multiply (710 yd) by (3 ft/1 yd) and that'll give you the width in ft. length = 634 m This one is a little tricker, but same principle. First convert meters to centimeters, like this: (634 m)(100 cm/1 m). Then take that number in cm and convert it into inches, knowing that 1 inch = 2.54 centimeters. So multiply the inches you have by (1 in/2.54 cm). Then you'll change that number into feet by dividing it by twelve, since there are twelve inches in each foot. Now you have all three measurements in feet. Just multiply them together to get the volume in ft³ and you're good to go! :)

8 0

3 years ago

Read 2 more answers

A high-jumper, having just cleared the bar, lands on an air mattress and comes to rest. Had she landed directly on the hard grou

Hoochie [10]

Answer:

e. the air mattress exerts the same impulse, but a smaller net avg force, on the high-jumper than hard-ground.

Explanation:

This is according to the Newton's second law and energy conservation that the force exerted by the hard-ground is more than the force exerted by the mattress.

The hard ground stops the moving mass by its sudden reaction in the opposite direction of impact force whereas the mattress takes a longer time to stop the motion of same mass in a longer time leading to lesser average reaction force.

Mathematical expression for the Newton's second law of motion is given as:

$F=\frac{dp}{dt}$ ............................................(1)