# Emmanuel

Popular questions and responses by Emmanuel
1. ## Science

In a simple the energy input is 120j if the efficiency of the machine is 80% calculate the energy output

2. ## physics

a body of mass 25kg moving at 3m/s on a rough horizontal floor is brought to rest after sliding through a distance of 2.5m on the floor. calculate the coefficient of sliding friction.

3. ## Physics

A battery of three cells in series each of emf 2v and internal 0.5 ohms is connected to 2ohms resistor in series with a parallel combination of two 3ohms resistors (a)draw the circult diagram (b)the effective of external resistance (c)the current in the

4. ## science

an athlete of mass 70.0kg runs a 100m race in 10s. calculate the kinetic energy possessed by the athlete.

5. ## Archimedes principle

An iron piece of mass 360g and a density of 6g/cm^3 is suspended by a rope so that is partially (halfway)in oil of density 0.9 g/cm^3.Find the tension (force) in the string.

6. ## chemistry

calculate the percentage by mass of silicon tetrachloride

7. ## Science Help Not sure

Within the Gaetz Lake Sanctuary in Red Deer, Alberta, is a looped trail that is 4 km long. Suppose a person walked all the way around the looped trail in 1 h, ending where he or she started. Which statement best describes this person’s motion over this

8. ## Science

1.The sound from a bolt of lighting travelled 4.08km in 12.0s. whats was the spped of the sound in metres per second? 0.340m/s 49.0m/s 340m/s 343m/s 2.A vehicle is travelling 1.0x10^2 km/h. what is the spped of the vehicle in metres per second? 28m/s

9. ## science

A vehicle is travelling 1.0x10^2 km/h. what is the spped of the vehicle in metres per second? 28m/s 27.8m/s 3.6x10^2m/s 1.0x10^4m/s

10. ## Further maths

If x is an acute angle, tanx =3/4,evaluate coax _sinx÷cosx+sinx

11. ## Science Help Not sure

A traffic-safety engineer is designing a deceleration lane. She is basing the length of this lane on the distance needed to slow down from 126 km/h to 65 km/h in 8.0 s. How long will the deceleration lane be? A. 2.1 x 10^2 m B. 3.8 x 10^2 m C. 4.2 x 10^2 m

12. ## Physics

1. A force of 40N at the end of a wire of length 4m and diameter 2mm process and extension of 0.24mm. Calculate; (a) stress on the wire (b) strain in the wire (c) Young's Modulous for the material of the wire (π=3.14)

13. ## Angles of elevation and depression

The teet of two vertical poles of height 3m and 7m are in line with a point P on the ground. The smaller pole being between the taller pole and P and at distance of 20m from P the angle of elevation of the top T of the taller pole from the top R of the

14. ## computer simulation

A grocery store has three checkout lanes (checkout 1, 2, and 3), each with a single checker. Shoppers arrive at the checkout area with interarrival times having an exponential distribution with mean 2.4 minutes. The shoppers enter the lane that has the

15. ## Science

9. The Pleistocene Epoch, from 1.7 million years ago to 10 000 years ago, was marked by A. a lack of oxygen B. the presence of warm, tropical seas C. the southern movement of the North American continent D. the formation of glaciers that covered parts of

16. ## Mathematics

. The three consecutive terms of an exponential sequence (G.P) are the second, third and sixth terms of a linear sequence (A.P). Find the common ratio of the exponential sequence.

17. ## math

Chad buys peanuts in 2-pound bags. He repackages them into bags that hold 5/6 pound of peanuts. How many 2-pound bags of peanuts should Chad buy so that he can fill the 5/6-pound bags without having any peanuts left over?

18. ## Economics

Consoder a monolist facing a linear demand Q=60-P/3. The monolist products with constant marginal costs c=3 and no fixed costs. Its marginal revenue function is MR=60-6Q A) plot demand function in a picture together with the marginal revenue curve and

19. ## marian university college

The molar constant-pressure heat capacity of a certain solid at 4.2 K is 0.43 J K−1 mol−1. What is its molar entropy at that temperature?

20. ## Maths

A box contain 40 pens of equal sizes.10 of them are green and 18 are red.if a pen is chosen at random from the box,what is the probability that is neither green nor red? Soln total number of pens=40 number of green pens=10 number of red pens=18 number of

21. ## science

a pupil of mass 50 kg runs a flight of 20 stairs each 25cm high in a time of 20 seconds (take g= N/kg calculate the pupil s gain in potential energy

22. ## calculus

h(t)=cot t a.) [pi/4,3pi/4] b.) [pi/6,pi/2] Find the average rate of change of the function over the give n interval and intervals. Please show step by step instructions. Thanks

23. ## math

If an aircraft flies on a bearing of 120 degrees from point A to B, what bearing should it take to fly from B to A?

24. ## Maths

A ladder leans against a vertical wall of height 12m.if the foot of the ladder is 5m away from the wall,calculate the length of the ladder.

25. ## Science

A baseball flew 19.6 m straight up into the air after being hit by a bat. How long should it take for the ball to return from its maximum height? A. 1.02 s B. 1.91 s C. 2.00 s D. 3.99 s

26. ## Any math tutor online? Help

Two companies charge these rates for printing a brochure : Company A charges \$175 for set up and 0.10 pet brochure Company B charges \$250 for set up and 0.07 pee brochure A linear system that model this situation is C=175 + 0.10n C =250+ 0.07 Where c is

27. ## Math

Jada, Nicholas, Nita, and Calvin shared \$60. Jada received 1/2 of the total amount of money Nicholas, Nita, and Calvin received. Nicholas received 2/3 of the total amount of money Nita and Calvin received. Nita received 3 times as much as calvin. (a) how

28. ## Maths

A boy went to a supermarket and spends 2/5 of his pocket money on biscuit, 1/4 on plantain chips and the remainder on drinks. i.wha fraction did he spend on plantain chips and biscuit ii.What fraction did he spend on drinks

29. ## Chemistry

Calculate the volume of carbon 4 oxide gas at s.t.p when 5g of zinc trioxocarbonate is heated strongly.

30. ## Chemistry

How many grams of commercial C2H4O2 (97% pure by mass) must be allowed to react with an excess of PCl3 to produce 75.0g of C2H3OCL if the reaction has a 78.2% yield?

31. ## science

3 identical point charges each one micro coulomb placed at vertices of an equilateral triangle 10cm apart calculate the force on each charge

32. ## psychology

How research methods are used to determine causes and solutions to psychological or work problems

33. ## physics

A mass of ideal gas of volume 400 cm3 at a temperature of 27 ˚C expands adiabatically until its volume is 500 cm3. Calculate the new temperature. The gas is then compressed isothermally until its pressure returns to the original value. Calculate the final

34. ## physics

A water vapour thermometer is calibrated at the ice and steam points and the saturation vapour pressures (s.v.p) are measured. The saturation vapour pressure Pθ is given by P  P01   2 , where P0 is the s.v.p at the ice point,

35. ## Physics

A projectile leaves the ground at an angle of 60degree to the horizontal.it initial kinetic energy is E. Neglecting air resistance, it kinetic energy at the highest point of the motion is

36. ## Science

which of the following is not scalar quantity. 0.20m 5.0m/s 10.0m/s[E] 110km/h

37. ## physics

Combining the statement written in question 19 with the mathematical statement of the 1st law of thermodynamics, show in not more than 6 steps that; du pdv T ds  1 

38. ## Math

Using ruler and pair of compasses only, construct a quadrilateral PQRS,such that/PQ/ =8cm ,QPS=105 , PQS=30, /PR/=9cm, and /RS/ =/RQ/

39. ## Chemistry

Describe briefly how pure dry crystals of calcium chloride can be obtained from its solution

40. ## Math

In a circle of radius 12cm a chord is drawn 3cm from the centre. Find the angle subtended at the centre

41. ## Further maths

The first term of an AP is equal to thrice the common difference. What is the sixth term of the AP,if the common difference is 8

42. ## science

A body of mass 20kg moving with a velocity of 8m/s collides with a stationary body of mass 10kg and the two stick together.They then move with a common velocity V.Find the value of V.

43. ## math

The position of an object moving in a straight line is given by the function , where s(t) represents distance traveled and t represents the time the object has been in motion. How long (to the nearest tenth) will it take the object to move 17 meters?

44. ## chemistry

Pt, (H2) 1atm | CH3COOH 0.1 M, CH3COONa 0.15M || NaBr 0.1M, AgBr(S) | Ag write the cathodic, anodic and final reactions.

45. ## physics

Write a mathematical statement for the change in entropy, ds, for the case where no work is done irrespective of the path.

46. ## physics

The density of a gas of relative molecular mass 28 at a certain temperature is 0.90 kgm-3. The root mean square speed of the gas molecules at that temperature is 602 ms-1. Assuming2 that the rate of diffusion of a gas is inversely proportional to the

47. ## physics

why an ice cube at 0 ˚C is more effective in cooling a drink than the same mass of water also at 0 ˚C

48. ## Physics

in air an object weighs 15N. when immersed in water it weighg 12. when immersed in another liquid it weighs 13N determine the density of the object and that of the liquid

49. ## Chemistry

After 0.6523g of CoCL2 .6H2O is heated, the residue has a mass of 0.3423g. Calculate the percent H2O in the hydrate. What is the formula of the hydrate

50. ## Chemistry

A is a solution of trioxonitrate (V) acid. HNO of unknown concentration B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution 25cm3 portion solution B required an average of 24.00cm3 of solution A for neutralization. Using 2 drop

51. ## algebra

A florist plans to make 5 Identical bridesmaid bouquets for a weeding. She budgeted £ 610 and she want to 24 flowers for each bouquet. She want to use three types of flowers namely; roses, tulips and lilies . A survey of prices shows roses cost £6,

52. ## Mathematics

A rectangular pyramid that measure 10cm by 7cm. Calculate A the surface area B.volume of the pyramid C.the sides of a triangle.

53. ## Physical science

Which of the following homogeneous and which are heterogeneous? Blood, carbon dioxide,Rock, steak,iron, concrete, air,oxygen, salt, milk.

54. ## Math

A commuter plane flies from City A to City B, a distance of 90 mi due north. Due to bad weather, the plane is redirected at take-off to a heading N 60° W (60° west of north). After flying 57 mi, the plane is directed to turn northeast and fly directly

55. ## chemistry

how many unpeeled electrons are in this configuration 1s2 2s2 2p6 3s2 3p3

56. ## PHYSICS

A mass of 2kg is dropped from a height of 3m.Neglecting air resistance,KE of the stone just b4 it hits the ground is ?

57. ## chemistry

60 cm of hydrogen diffused through a porous membrane in 10 minutes. The same volume of gas G diffused through the same membrane in 37.4 minutes. Determine the relative molecular mass of

58. ## science

A block of wood is weighed on a beam balance.its mass is 54g.The density of the block is1.8g/cm`3.Find volume

59. ## science

A measuring cylinder contains 50cm`3 of water.A stone has a mass of 1.75g.The stone is lowered into the cylinder, the level of the water rises to 52.5cm`3.Calculate the density of the stone

60. ## maths

Find the median of 3,6,10,13, 14,17,19 and 22

61. ## Math

Wilma drove at an average speed of 35 mi/h from her home in City A to visit her sister in City B. She stayed in City B 15 hours, and on the trip back averaged 40 mi/h. She returned home 41 hours after leaving. How many miles is City A from City B?

62. ## physics

a stone projected horizontally from the top of a tower with a speed of 4m/s lands on the level ground at a horizontal distance 25m from the foot of the tower. calculate the height[g=10m/s2]. is it u squared divided by 2g

63. ## Science

A skydiver steps out of a helicopter hovering thousands of metres above ground. After 3.5 s of free fall the skydiver pulls the rip cord. What is the skydiver’s displacement during the 3.5 s of free fall?

64. ## statistics

a study of 40 professors showed they spent on average 13.6 minutes correcting a student papers. Given a standard deviation of 17, the 90% confidence interval of the mean time for all the test papers is what?

65. ## chemistry

Three gases (8.00 of methane, , 18.0 of ethane, , and an unknown amount of propane, ) were added to the same 10.0- container. At 23.0 , the total pressure in the container is 3.50 . Calculate the partial pressure of each gas in the container.

66. ## physics

Under what condition (if any) does a moving body experience no energy even though there is a net force acting on it?

67. ## physics

A woman is unhappy with the rate at which eggs cook in a saucepan of boiling water. State in 2 words only, the method she could use to get the eggs to cook fastest.

68. ## Mathematics

The bearings of ships A AND B from port p are 2.25 degree and 116 respectively.ship A is 3.9km from ship B on a bearing of 258 degree. Calculate the distance of ship A from p

69. ## Math

Sage has a hot dog stand. Last week he spent \$13 for hot dogs and supplies. He earned \$25. What was his profit?

70. ## physics

A man of mass 50kg ascend a fight of stairs 5m high in 55 seconds.if acceleration due to gravity is 10ms the power expand is what

71. ## math

Evaluate 3 log 2 + log 20 _ log 1.6

72. ## Math

a number is added to 10and12.if the product of the sum obtained is48,find the number

73. ## Math

one angle of an octagon is 56 degree find each of the other angle if they are equal to each other

74. ## Pre-Algebra

8/2=x+3/4, solve for x

75. ## Chemistry

A student heats 64.05 grams of nickel to 97.80 °C and then drops it into a cup containing 81.11 grams of water at 21.79 °C. She measures the final temperature to be 27.84 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter

76. ## Chemistry

In the laboratory, a student heats 96.27 grams of zinc to 98.06 °C and then drops it into a cup containing 76.46 grams of water at 22.44 °C. She measures the final temperature to be 30.31 °C. Using the accepted value for the specific heat of zinc (See

77. ## math

Solve the simultaneous equation logx+logy=4 I would appreciate it if you help me

78. ## Physics

An object is dropped from 320m high. Find the time of motion and velocity when it hits the ground.

79. ## Math

An american car travels 32 miles on one gallon. A European car travels 12.7 kilometers on one liter of gas. Wich car gets better gas mileage? Explain your reasoning.

80. ## Chemistry

A Metal X forms two different chloride. If 12.7g of chloride A and 16.3g of chloride B contains 7.1g and 10.7g of chlorine respectively, show that the figure agree with the law of multiple proportion. Write their formulae

81. ## Physics

A uniform beam 6m long weighing 4kg rests on supports p and q placed left and right 1metre from each end of the beam. Weight of mass 10kg and 8kg are placed near p and q respectively one each end of the beam. Calculate the reactions at p and q.

82. ## math

show the limit of |X| if X tend to 0

83. ## math

Byron wants to use the distributive property to rewrite the addition problem shown so that the numbers left in the parentheses have no common factor except 1. (48 + 36) Which is an equivalent expression that has numbers in the parentheses whose only common

84. ## civic education

in what ways can leaders promote the interest of their followers?

85. ## Physic

Two force which is 10n are perpendicular to each other if one of them makes an angle of 60 then calculate the magnitude

86. ## CHEMISTRY

STEPS ON CALCULATING DEHYDRATION OF CRYSTALS

87. ## Physic 101

in suv of which the total mass is 800 kg is travelling with an initial velocity of 200m/s suddenly observe a stationary dog 50m ahead along its path if the driver exerts a break of 2000N,what would happen?

88. ## Chemistry

what volume would 1.31g of hydrogen occupy at 2.0atm and 127°c?

89. ## bio

How Does exponential growth affects the 5 scientific principles of sustainability,reliance of solar energy,biodiversity,population control and nutrient recycling

90. ## phy 101

if he travels 7km N 30 degree E and 10km east find the resultant displacement

91. ## math

john's age in the next ten years will four times his age five years ago. How old is john now?

92. ## pysics

three identical point charges each Q coulombs are placed at the vertices of an equilatwral triangle 20cm apart.calculate the force on each charge

93. ## Physics

A stone, 2kg is projected vertically at a velocity of 5m/s at an Angle of 60° Calculate I.Time taken to attain maximum height II.maximum height reached III.The range

94. ## chemistry

A metal x form different chlorides.If 12.7g of chloride A and 16.3g of chloride B contains 7.1g and 10.7g of chlorine respectively show that the figures agree with the law of multiple proportions. write their formular

95. ## maths

A bicycle has a radius of 28cm How far does it travel in four complete turns

96. ## physics

A catapult used to hold a stone of mass 500grammes is extended by 2cm with an applied force F. if the stone leaves with a velocity 40ms-1, the value of F is.

97. ## chemistry

how many unpaired electrons are in this configuration 1s2 2s2 2p6 3s2 3p3

98. ## Science

What is the effect on molarity for NaOH when balance used to weigh KHP is not properly calibrated and always reads 0.15 g too low.

99. ## maruco

The electrons in the d–orbitals – are they from the metal or the ligands.why?