Physics, 02.07.2019 07:00 ZenMoss

Worldâs tallest building. suppose that you drop a marble from the top of the burj khalifa building in dubai, which is about 830 m tall. if you ignore air resistance, (a) how long will it take for the marble to hit the ground? (b) how fast will it be moving just before it hits?

Answers: 1

Show answers

Answers

a) 13 seconds b) 130 m/s The formula for the distance an object moves while under constant acceleration is d = 1/2AT^2. So let's define d as 830 m, A as 9.8m/s^2, and solve for T 830 m = 1/2 9.8 m/s^2 T^2 830 m = 4.9 m/s^2 T^2 Divide both sides by 4.9 m/s^2 169.3878 s^2 = T^2 Take the square root of both sides 13.01491 s = T Since we only have 2 significant figures, round the result to 13 seconds which is the answer to the first part of the question. To find out how fast the marble is moving, just multiply T and A together 13 s * 9.8 m/s^2 = 127.4 m/s Since we only have 2 significant figures, round the result to 130 m/s.

Answer from: BrainGeek4848

It will take $13.01\rm sec$ for the marble to hit the ground.

It will be moving $127.49\rm m/sec$ fast just before it hits.

Explanation:

Given information:

Initial velocity, $u=0\rm m/s$

acceleration due to gravity is positive as (motion of marble is in same direction of motion)

$a=g=9.8 \rm m/s^2$

Height of Burj khalifa $h=830\rm m$

By using equation of motion,

(a) u=0,

$h=ut+\frac{1}{2}\times a t^2=\frac{1}{2}gt^2$

$830\rm m=\frac{1}{2}\times 9.8\rm m/s^2\times t^2$

$t=\sqrt\frac{830\times2}{9.8}=13.01\rm sec$

It will take $13.01\rm sec$ for the marble to hit the ground.

(b)By using,

u=0

v=u+at=gt

$v=9.8\rm m/s^2\times(13.01\rm s)=127.49\rm m/s$

Hence, It will be moving $127.49\rm m/sec$ fast just before it hits.

For more details please refer the link:

link

Answer from: Quest

Ifeel like lily and ledbetter had a fair pay act just because it was necessary especially at those times

Answer from: Quest

so here is the information for current research:

-nrel's geothermal analysts, scientists, and engineers perform a full range of research from developing advanced methods of locating and accessing geothermal resources to exploring innovative technologies to extract and produce clean energy from the heat of the earth

and here is the information for the technology of geothermal energy:

-it's clean and sustainable

-resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma

-almost everywhere, the shallow ground or upper 10 feet of the earth's surface maintains a nearly constant temperature between 50° and 60°f (10° and 16°c)

-geothermal heat pumps can tap into this resource to heat and cool buildings

-a geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building

-in the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system

-in the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger

-the heat removed from the indoor air during the summer can also be used to provide a free source of hot water

Another question on Physics

Physics, 21.06.2019 22:50

Two horizontal plates with infinite length and width are separated by a distance h in the z direction. the bottom plate is moving at a velocity u. the incompressible fluid trapped between the plates is moving in the positive x-direction with the bottom plate. align gravity with positive z. assume that the flow is fully-developed and laminar. if the systems operates at steady state and the pressure gradient in x-direction can be ignored, do the following: 1. sketch your system 2. identify the coordinate system to be used. 3. show your coordinates and origin point on the sketch. list all your assumptions. 5. apply the continuity equation to your system. nts of navier stokes equations of choice to your system 7. solve the resulting differential equation to obtain the velocity profile within the system make sure to list your boundary conditions. check units of velocity 8. describe the velocity profile you obtain using engineering terminology. sketch that on the same sketch you provided in (1). 9. obtain the equation that describes the volumetric flow rate in the system. check the units.

Answers: 2

Answer

Physics, 22.06.2019 00:10

I'm kinda lost ! 1. when marilyn takes her pet dog for a walk, the dog walks at a veryconsistent pace of 0.55 m/s. draw a position-time graph to representmarilyn's dog walking the 19.8 m distance from the front of her house tothe nearest fire hydrant.2. both car a and car bleave school when a stopwatch reads zero. car atravels at a constant 75 km/h, and car b travels at a constant 85 km/h.a) draw a position-time graph showing the motion of both cars. howfar are the two cars from school when the stopwatch reads 2 hrs? calculate the distances and show them on your graph.b) both cars passed a gas station 120 km from the school. when dideach car pass the gas station? calculate the times and show themon your graph.3. the figure below shows the position-time graph showing a shopper'smovement up and down the aisle at a store.a) write a story describing the shopper's movements at the store.b) when does the shopper have a position of 6 m? c) how much time passes between when the shopper enters the aisleand when he gets to a position of 12 m? what is the shopper's averagevelocity between 37 s and 46 s?

Answers: 3

Answer

Physics, 22.06.2019 02:00

Write the correct abbreviation for each metric unit

Answers: 1

Answer

Physics, 22.06.2019 11:30

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? yourunits 3. a clothes dryer uses about 2 amps of current from a 240 volt line. how much power does it use? yourunits 4.

Answers: 1

Answer

You know the right answer?

Worldâs tallest building. suppose that you drop a marble from the top of the burj khalifa building i...

Questions