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Question Number 29265 Answers: 0 Comments: 0

An electric pump with efficiency of 70% raises water to a height of 15m . If water is delivered at the rate of 350 dm^3 per minute. (i) what is the power rating of the pump ? (mass of 1 dm^3 = 1 kg) (ii) what is the energy lost by the pump ? (g = 10 m/s^2 ) (Answer: 1250W. 22.5 KJ)

$$\mathrm{An}\:\mathrm{electric}\:\mathrm{pump}\:\mathrm{with}\:\mathrm{efficiency}\:\mathrm{of}\:\:\:\mathrm{70\%}\:\:\mathrm{raises}\:\mathrm{water}\:\mathrm{to}\:\mathrm{a}\:\mathrm{height}\:\mathrm{of}\:\:\mathrm{15m} \\ $$$$.\:\mathrm{If}\:\mathrm{water}\:\mathrm{is}\:\mathrm{delivered}\:\mathrm{at}\:\mathrm{the}\:\mathrm{rate}\:\mathrm{of}\:\:\mathrm{350}\:\mathrm{dm}^{\mathrm{3}} \:\mathrm{per}\:\mathrm{minute}.\:\: \\ $$$$\left(\mathrm{i}\right)\:\mathrm{what}\:\mathrm{is}\:\mathrm{the}\:\mathrm{power}\:\mathrm{rating}\:\mathrm{of}\:\mathrm{the}\:\mathrm{pump}\:?\:\:\:\left(\mathrm{mass}\:\mathrm{of}\:\mathrm{1}\:\mathrm{dm}^{\mathrm{3}} \:=\:\mathrm{1}\:\mathrm{kg}\right) \\ $$$$\left(\mathrm{ii}\right)\:\:\mathrm{what}\:\mathrm{is}\:\mathrm{the}\:\mathrm{energy}\:\mathrm{lost}\:\mathrm{by}\:\mathrm{the}\:\mathrm{pump}\:?\:\:\:\left(\mathrm{g}\:=\:\mathrm{10}\:\mathrm{m}/\mathrm{s}^{\mathrm{2}} \right) \\ $$$$\left(\mathrm{Answer}:\:\:\:\mathrm{1250W}.\:\:\:\:\mathrm{22}.\mathrm{5}\:\mathrm{KJ}\right) \\ $$

Question Number 29264 Answers: 1 Comments: 0

there are 25 persons in a conical tent every person needs an area of 4 sq m on the ground under the tent. if height if the tent is 18m.find the volume of the tent.

$$\mathrm{there}\:\mathrm{are}\:\mathrm{25}\:\mathrm{persons}\:\mathrm{in}\:\mathrm{a}\:\mathrm{conical}\:\mathrm{tent} \\ $$$$\mathrm{every}\:\mathrm{person}\:\mathrm{needs}\:\mathrm{an}\:\mathrm{area}\:\mathrm{of}\:\mathrm{4}\:\mathrm{sq}\:\mathrm{m}\: \\ $$$$\mathrm{on}\:\mathrm{the}\:\mathrm{ground}\:\mathrm{under}\:\mathrm{the}\:\mathrm{tent}.\:\mathrm{if} \\ $$$$\mathrm{height}\:\mathrm{if}\:\mathrm{the}\:\mathrm{tent}\:\mathrm{is}\:\mathrm{18m}.\mathrm{find}\:\mathrm{the}\:\mathrm{volume} \\ $$$$\mathrm{of}\:\mathrm{the}\:\mathrm{tent}. \\ $$

Question Number 29273 Answers: 0 Comments: 4

Question Number 29260 Answers: 0 Comments: 0

The eriodic time of a simple pendulum is given by T=2π(√(L/g)). if L=100±0.1cm(s.e) and the time s for 10 ossilations are: 48.2,48.2,48.7,48.5,48.4,48.2,48.4, 48.6,48.5,48.2. calcukate g and the standard error involved.

Question Number 29259 Answers: 1 Comments: 0

solve the equation 2x+3y=5 3x+4y=4

$${solve}\:{the}\:{equation} \\ $$$$\mathrm{2}{x}+\mathrm{3}{y}=\mathrm{5} \\ $$$$\mathrm{3}{x}+\mathrm{4}{y}=\mathrm{4}\: \\ $$

Question Number 29308 Answers: 2 Comments: 0

Solve: w^3 = − 16

$$\mathrm{Solve}:\:\:\:\mathrm{w}^{\mathrm{3}} \:=\:−\:\mathrm{16} \\ $$

Question Number 29249 Answers: 1 Comments: 1

Question Number 29241 Answers: 1 Comments: 0

Question Number 29242 Answers: 0 Comments: 0

Question Number 29254 Answers: 1 Comments: 1

Question Number 29222 Answers: 1 Comments: 0

3x−4y=12, xy=2

$$\mathrm{3}{x}−\mathrm{4}{y}=\mathrm{12},\:{xy}=\mathrm{2} \\ $$

Question Number 29217 Answers: 1 Comments: 0

The velocity of a physical system is given by V={(√((p+1/n)))}/x where p=pressure. Find the dimensions of n and x

$${The}\:{velocity}\:{of}\:{a}\:{physical}\:{system} \\ $$$${is}\:{given}\:{by}\:{V}=\left\{\sqrt{\left({p}+\mathrm{1}/{n}\right)}\right\}/{x} \\ $$$${where}\:{p}={pressure}.\:{Find}\:{the} \\ $$$${dimensions}\:{of}\:{n}\:{and}\:{x} \\ $$

Question Number 29216 Answers: 1 Comments: 0

A horizontal force of 0.8N is required to pull a 5kg block across a table top at a constant speed. With the block initially at rest,a 20g bullet fired horizontally into the block to slide 1.5m before coming to rest again.Determine the speed v of the bullet,where the bullet is assumed to be embedded in the block.

$${A}\:{horizontal}\:{force}\:{of}\:\mathrm{0}.\mathrm{8}{N}\:{is} \\ $$$${required}\:{to}\:{pull}\:{a}\:\mathrm{5}{kg}\:{block}\:{across} \\ $$$${a}\:{table}\:{top}\:{at}\:{a}\:{constant}\:{speed}. \\ $$$${With}\:{the}\:{block}\:{initially}\:{at}\:{rest},{a} \\ $$$$\mathrm{20}{g}\:{bullet}\:{fired}\:{horizontally}\:{into} \\ $$$${the}\:{block}\:{to}\:{slide}\:\mathrm{1}.\mathrm{5}{m}\:{before} \\ $$$${coming}\:{to}\:{rest}\:{again}.{Determine} \\ $$$${the}\:{speed}\:{v}\:{of}\:{the}\:{bullet},{where} \\ $$$${the}\:{bullet}\:{is}\:{assumed}\:{to}\:{be} \\ $$$${embedded}\:{in}\:{the}\:{block}. \\ $$

Question Number 29213 Answers: 0 Comments: 1

Two masses m and 2m,approach each l along a path at right angle to each other and move off at 2m/s at angle 37° to the original direction of mass m. What where the initial speeds of the two particles?

$${Two}\:{masses}\:{m}\:{and}\:\mathrm{2}{m},{approach} \\ $$$${each}\:{l}\:{along}\:{a}\:{path}\:{at}\:{right} \\ $$$${angle}\:{to}\:{each}\:{other}\:{and}\:{move}\:{off} \\ $$$${at}\:\mathrm{2}{m}/{s}\:{at}\:{angle}\:\mathrm{37}°\:{to}\:{the} \\ $$$${original}\:{direction}\:{of}\:{mass}\:{m}. \\ $$$${What}\:{where}\:{the}\:{initial}\:{speeds}\:{of} \\ $$$${the}\:{two}\:{particles}? \\ $$

Question Number 29212 Answers: 1 Comments: 1

A block of wood of mass 0.6kg is balanced on top of vertical port 2m high.A 10g bullet is fired horizontally into the block and the embedded bullet land at a 4m from the base of the port.Find the initial velocity of the bullet.

$${A}\:{block}\:{of}\:{wood}\:{of}\:{mass}\:\mathrm{0}.\mathrm{6}{kg}\:{is} \\ $$$${balanced}\:{on}\:{top}\:{of}\:{vertical}\:{port} \\ $$$$\mathrm{2}{m}\:{high}.{A}\:\mathrm{10}{g}\:{bullet}\:{is}\:{fired} \\ $$$${horizontally}\:{into}\:{the}\:{block}\:{and} \\ $$$${the}\:{embedded}\:{bullet}\:{land}\:{at}\:{a}\:\mathrm{4}{m} \\ $$$${from}\:{the}\:{base}\:{of}\:{the}\:{port}.{Find} \\ $$$${the}\:{initial}\:{velocity}\:{of}\:{the}\:{bullet}. \\ $$

Question Number 29209 Answers: 1 Comments: 4