# High quality video lessons and tutorials

**279 Video Lessons**

- A man lifts a weight of 300N through a vertical height of 2m, in 6 seconds. Determine the power developed.
A man lifts a weight of 300N through a vertical height of 2m, in 6 seconds. Determine the power developed.

Form 3, Physics: Work, Energy, Power and MachinesDate posted: March 5, 2019.

- A pipe of diameter 12m is connected to another of diameter 18m. If water flows in the wider at the speed of 2m/s, determine his speed of water in the narrower pipe?
A pipe of diameter 12m is connected to another of diameter 18m. If water flows in the wider at the speed of 2m/s, determine his speed of water in the narrower pipe?

Form 2, Physics: Fluid flowDate posted: March 5, 2019.

- The figure below shows a micrometer screw gauge being used to measure the diameter of a metal rod.
The figure below shows a micrometer screw gauge being used to measure the diameter of a metal rod. What is the reading shown?

Form 2, Physics: Measurements 2Date posted: March 5, 2019.

- A Girl in a school in the Coast region plans to make a barometer, using sea water of density 1030kgm
^{-3}. If the atmospheric pressure is 103000Nm^{-2}. Determine the minimum length of the tube she will use. Take g =10N/kg.A Girl in a school in the Coast region plans to make a barometer, using sea water of density 1030kgm

^{-3}. If the atmospheric pressure is 103000Nm^{-2}. Determine the minimum length of the tube she will use. Take g =10N/kg.

Form 1, Physics: PressureDate posted: March 5, 2019.

- The figure below shows a 1 meter long uniform metal bar in equilibrium.
The figure below shows a 1 meter long uniform metal bar in equilibrium. Determine the weight of the metal bar.

Form 2, Physics: Turning effect of forceDate posted: March 5, 2019.

- An oil drop forms a circular patch of an area 5.0 x 10
^{-13}cm^{2}. If the drop has a volume of 9.0 x 10^{-14}cm^{3}, estimate the diameter of the oil molecule.An oil drop forms a circular patch of an area 5.0 x 10

^{-13}cm^{2}. If the drop has a volume of 9.0 x 10^{-14}cm^{3}, estimate the diameter of the oil molecule.

Form 2, Physics: Measurements 2Date posted: March 5, 2019.

- A girl ties a stone of mass 250g with a piece of thread. Holding the other end of the thread at 45cm in length, she makes the stone revolve in a circle in a vertical plane at a constant speed.
A girl ties a stone of mass 250g with a piece of thread. Holding the other end of the thread at 45cm in length, she makes the stone revolve in a circle in a vertical plane at a constant speed. If the stone is making 3 revolutions, per second calculate; a) The angular velocity. b) Tension in the...

Form 4, Physics: Circular motionDate posted: March 5, 2019.

- The level of water in a measuring cylinder rises from the 50cm
^{3}mark to 55.7cm^{3}marks when a metal block weighing 45g is submerged in the water in the cylinder.Calculate the density of the metal block.The level of water in a measuring cylinder rises from the 50cm

^{3}mark to 55.7cm^{3}marks when a metal block weighing 45g is submerged in the water in the cylinder.Calculate the density of the metal block.

Form 1, Physics: Measurements 1Date posted: March 5, 2019.

- In an experiment to determine the density of solid S which is not soluble in water. A student obtained the following;
In an experiment to determine the density of solid S which is not soluble in water. A student obtained the following; - Mass of empty density bottle= 20g - Mass of density bottle when full of water =45g - Mass of density bottle with small quantity of solid S =152g - Mass of density bottle with...

Form 1, Physics: Measurements 1Date posted: March 5, 2019.

- An electric crane lifts a load of 2000kg through a vertical distance of 3.0m in 6 seconds
Determine:
An electric crane lifts a load of 2000kg through a vertical distance of 3.0m in 6 seconds Determine: i)The work done ii) The power developed by the crane. iii).The efficiency of the crane if it is operated by an electric motor rated 12.5kw.

Form 3, Physics: Work, Energy, Power and MachinesDate posted: March 5, 2019.

- In 100m race there are three main competitors namely Simiyu, Ondiek and Kamau. Simiyu is three times likely to win as Ondiek, while Ondiek is twice as likely to win as Kamau.
In 100m race there are three main competitors namely Simiyu, Ondiek and Kamau. Simiyu is three times likely to win as Ondiek, while Ondiek is twice as likely to win as Kamau. Find the probability that a) Ondiek wins the race b) Either Simiyu or Kamau

Form 3, Mathematics: ProbabilityDate posted: March 5, 2019.

- Solve the inequality below and state the integral values of your solution.
Solve the inequality below and state the integral values of your solution. 2(3x-4)

Form 2, Mathematics: Linear InequalitiesDate posted: March 5, 2019.

- A bus and a car leave Nairobi at 7.30am and 9.30am respectively. If their speeds are 60km/h and 100km/h respectively, find the time when the car catches up with the bus.
A bus and a car leave Nairobi at 7.30am and 9.30am respectively. If their speeds are 60km/h and 100km/h respectively, find the time when the car catches up with the bus.

Form 2, Mathematics: Linear MotionDate posted: March 5, 2019.

- Find the gradient of y=x
^{2}-3x at x=1Find the gradient of y=x

^{2}-3x at x=1

Form 4, Mathematics: CalculusDate posted: March 5, 2019.

- Find the values of x in the question below

Form 3, Mathematics: MatricesDate posted: March 5, 2019.

- In a book store, books packed in cartons are arranged in rows such that there are 50 cartons in the first row, 48 cartons in the next row, 46 in the next and so on.
In a book store, books packed in cartons are arranged in rows such that there are 50 cartons in the first row, 48 cartons in the next row, 46 in the next and so on. a) How many cartons will be there in the 8th row? b) If there are 20 rows in total, find total number of cartons in the book...

Form 3, Mathematics: Sequences and SeriesDate posted: March 5, 2019.

- The 2nd, 4th and 7th terms of an AP are the first 3 consecutive terms of a GP. If the common difference of the AP is 2 , find the common ratio of the G.p
The 2nd, 4th and 7th terms of an AP are the first 3 consecutive terms of a GP. If the common difference of the AP is 2 , find the common ratio of the G.p

Form 3, Mathematics: Sequences and SeriesDate posted: March 5, 2019.

- Oketch sells his car to Jane and makes a profit of 17%. Jane sells the same car to Issa at Sh.300,000, making a loss of 10%.Determine the price at which Oketch bought the car.
Oketch sells his car to Jane and makes a profit of 17%. Jane sells the same car to Issa at Sh.300,000, making a loss of 10%.Determine the price at which Oketch bought the car.

Form 1, Mathematics: Commercial Arithmetic 1Date posted: March 5, 2019.

- A straight line passes through points A (-2, 6) and B (4, 2).M is the midpoint of line AB. Find the
co-ordinates of M.
A straight line passes through points A (-2, 6) and B (4, 2).M is the midpoint of line AB. Find the co-ordinates of M.

Form 1, Mathematics: Co-ordinates and graphsDate posted: March 5, 2019.

- A rectangle whose area is 96m
^{2}is such that its length is 4m longer than its width.A rectangle whose area is 96m

^{2}is such that its length is 4m longer than its width. Find a) Its dimensions. b) Its perimeter.

Form 2, Mathematics: Quadratic Equations and ExpressionsDate posted: March 5, 2019.

- Use the information in the table about group 1 elements to answer the questions that follow
Use the information in the table about group 1 elements to answer the questions that follow When the group 1 elements react with water, hydrogen gas is given off. The...

Form 2, Chemistry: The structure of the atom and the Periodic tableDate posted: March 5, 2019.

- An organic compound J has the following percentage by mass, carbon, 64.86%, hydrogen, 13.51% and
the rest oxygen. The relative molecular mass of the compound is 74.
An organic compound J has the following percentage by mass, carbon, 64.86%, hydrogen, 13.51% and the rest oxygen. The relative molecular mass of the compound is 74. Work out the molecular formula of compound J. [C=12. H=1 O=16]

Form 3, Chemistry: Mole ConceptDate posted: March 5, 2019.

- Complete the table below to show the number of the sub-atomic particles of the given nuclides. X and Y are not actual chemical symbols.
Complete the table below to show the number of the sub-atomic particles of the given nuclides. X and Y are not actual chemical symbols.

Form 2, Chemistry: The structure of the atom and the Periodic tableDate posted: March 5, 2019.

- 100cm³ of 2M nitric acid reacted with 12.5g of a carbonate of metal M. (MCO
_{3}) according to the following equation100cm³ of 2M nitric acid reacted with 12.5g of a carbonate of metal M. (MCO

_{3}) according to the following equation a).Calculate the number of moles of...

Form 3, Chemistry: Mole ConceptDate posted: March 5, 2019.

- 120cm
^{3}of nitrogen gas diffuses through a membrane in forty seconds. How long will it take 240cm^{3}of carbon (IV) oxide to diffuse through the same membrane (C=12,N=14,O=16)120cm

^{3}of nitrogen gas diffuses through a membrane in forty seconds. How long will it take 240cm^{3}of carbon (IV) oxide to diffuse through the same membrane (C=12,N=14,O=16)

Form 3, Chemistry: Gas LawsDate posted: March 5, 2019.

- 10g of ethanol (C
_{2}H_{5}OH) were completely burnt in air. The heat evolved caused the temperature of 400cm^{3}of water to change from 20^{0}C to 85^{0}C.10g of ethanol (C

_{2}H_{5}OH) were completely burnt in air. The heat evolved caused the temperature of 400cm^{3}of water to change from 20^{0}C to 85^{0}C. Calculate the molar enthalpy of combustion of ethanol. (H = 1, C = 12, O = 16. Specific heat capacity...

Form 4, Chemistry: Energy changes in chemical and physical processesDate posted: March 4, 2019.

- Fertilizers are added to the soil to improve crop yields. A farmer has a choice of two fertilizers,
ammonium nitrate NH
_{4}NO_{3}or diammonium hydrogen phosphate (NH_{4)2}HPO_{4})Fertilizers are added to the soil to improve crop yields. A farmer has a choice of two fertilizers, ammonium nitrate NH

_{4}NO_{3}or diammonium hydrogen phosphate (NH_{4)2}HPO_{4}.Show by calculation which of these fertilizers contains the greater percentage of...

Form 3, Chemistry: Nitrogen and its CompoundsDate posted: March 4, 2019.

- In an experiment to determine the solubility of solid Y in water at 30
^{0}C the following results were obtained.In an experiment to determine the solubility of solid Y in water at 30

^{0}C the following results were obtained. Mass of empty evaporating dish = 26.2g Mass of evaporating dish + saturated solution = 42.4g Mass of evaporating dish + dry solid = 30.4g Use the...

Form 4, Chemistry: Acids,bases and saltsDate posted: March 4, 2019.

- The table below shows the relative atomic masses and the percentage abundance of the isotopes L
_{1}and L_{2}of element L.The table below shows the relative atomic masses and the percentage abundance of the isotopes L

_{1}and L_{2}of element L. Calculate the relative atomic mass...

Form 2, Chemistry: The structure of the atom and the Periodic tableDate posted: March 4, 2019.

- A fixed mass of a gas has a volume of 250cm
^{3}at a temperature 27°C and 750mmHg pressure. Calculate the volume the gas would occupy at 42°C and 750mmHg pressure. (0°C = 273K)A fixed mass of a gas has a volume of 250cm

^{3}at a temperature 27°C and 750mmHg pressure. Calculate the volume the gas would occupy at 42°C and 750mmHg pressure. (0°C = 273K)

Form 3, Chemistry: Gas LawsDate posted: March 4, 2019.