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- A.G.M tube registers an initial count rate of 3200 counts for a certain substance and 100 counts 30 hours later.
What is half-life of this substance.(Solved)
A.G.M tube registers an initial count rate of 3200 counts for a certain substance and 100 counts 30 hours later.
What is half-life of this substance.
Date posted: May 27, 2019. Answers (1)
- The threshold frequency of sodium is 5.6 x 1014Hz. Planck's constant = 6.6 x 10-34Js. Find;(i) Work function of sodium (ii) The kinetic energy of...(Solved)
The threshold frequency of sodium is 5.6 x 1014Hz. Planck's constant = 6.6 x 10-34Js. Find;
(i) Work function of sodium
(ii) The kinetic energy of the ejected electrons when sodium is shone with light of frequency 8.6 x 1014Hz.
Date posted: May 27, 2019. Answers (1)
- At a hydroelectric power station, three turbines are 100 m below the surface of a reservoir.
The surface area of the reservoir is 1.5 x 103...(Solved)
At a hydroelectric power station, three turbines are 100 m below the surface of a reservoir.
The surface area of the reservoir is 1.5 x 103 km2. Water flows through channels from the reservoir to the turbines until the level of water in the reservoir falls by 1.0 cm after 24 hours,if 20% of energy is lost in the form of heat as the water travels through the channels, estimate
the;
(i) Total energy available for the turbines in this 24 hours.
(ii) The average rate of working of each turbine.
Date posted: May 27, 2019. Answers (1)
- You are provided with two identical cells. Two lamps and a switch.
(i) Draw a circuit diagram that would ensure that the bulbs have maximum brightness....(Solved)
You are provided with two identical cells. Two lamps and a switch.
(i) Draw a circuit diagram that would ensure that the bulbs have maximum brightness.
(ii) State one advantage of using such an arrangement in (i) above to light a whole house with many bulbs.
Date posted: May 27, 2019. Answers (1)
- When the switch is closed in the figure below, the millimeter reads 75 mA. Determine the
internal resistance of the cell.(Solved)
When the switch is closed in the figure below, the millimeter reads 75 mA. Determine the
internal resistance of the cell.
Date posted: May 27, 2019. Answers (1)
- The initial mass of radioactive substance is 20 g. The substance has a half life of 2 years.
Determine the mass remaining after 20 years.(Solved)
The initial mass of radioactive substance is 20 g. The substance has a half life of 2 years.
Determine the mass remaining after 20 years.
Date posted: May 27, 2019. Answers (1)
- Below is a nuclear reaction.
(i) Identify radiation K.
(ii) Determine the value of x and y.(Solved)
Below is a nuclear reaction.
(i) Identify radiation K.
(ii) Determine the value of x and y.
Date posted: May 27, 2019. Answers (1)
- The diagram below shows a ray of light travelling between water glass interface.
Calculate the value of i given that ang = 1.52 and anw =...(Solved)
The diagram below shows a ray of light travelling between water glass interface.
Calculate the value of i given that ang = 1.52 and anw = 4/3.
Date posted: May 27, 2019. Answers (1)
- Using the circuit shown in figure below, calculate the effective capacitance.(Solved)
Using the circuit shown in figure below, calculate the effective capacitance.
Date posted: May 27, 2019. Answers (1)
- Two springs of negligible weight of spring constant K1 = 24 N/m and K2 = 48 N/m respectively
are connected end to end and suspended from...(Solved)
Two springs of negligible weight of spring constant K1 = 24 N/m and K2 = 48 N/m respectively
are connected end to end and suspended from a fixed point as shown below.
Determine;
I the total extension when a mass of 1.2 kg is hung from the lower end.
II the constant of the combination
Date posted: May 27, 2019. Answers (1)
- The figure below shows a horizontal tube with two vertical tubes X and Y of equal diameter. Water flows through the horizontal tube from right...(Solved)
The figure below shows a horizontal tube with two vertical tubes X and Y of equal diameter. Water flows through the horizontal tube from right to left.
(i) Indicate the water levels in the tube X and tube Y.
(ii) Explain your observation in (i)
Date posted: May 27, 2019. Answers (1)
- State one advantage of an electromagnet as compared to a permanent magnet.(Solved)
State one advantage of an electromagnet as compared to a permanent magnet.
Date posted: May 27, 2019. Answers (1)
- An immersion water heater rated 1800 w is used to heat water from 100C to 900C. Calculate the time taken, if the mass of water...(Solved)
An immersion water heater rated 1800 w is used to heat water from 100C to 900C. Calculate the time taken, if the mass of water is 6 kg. (Take specific heat capacity of water as 4200J kg -1K-1)
Date posted: May 27, 2019. Answers (1)
- A student heated some pure water and noticed it boiled at 960C instead of 1000C. If the thermometer was not faulty, what is the possible...(Solved)
A student heated some pure water and noticed it boiled at 960C instead of 1000C. If the thermometer was not faulty, what is the possible cause for this?
Date posted: May 27, 2019. Answers (1)
- A body starts from rest and accelerated uniformly at 8 m/s2. Calculate the distance traveled
by the body in 10 seconds.(Solved)
A body starts from rest and accelerated uniformly at 8 m/s2. Calculate the distance traveled
by the body in 10 seconds.
Date posted: May 27, 2019. Answers (1)
- The figure below shows a pulley system for lifting heavy object.
(i) State the velocity ratio of the pulley system.
(ii) If the efficiency of the...(Solved)
The figure below shows a pulley system for lifting heavy object.
(i) State the velocity ratio of the pulley system.
(ii) If the efficiency of the machine is 80%. Calculate the mechanical advantage of the system.
(iii) Determine the effort applied.
Date posted: May 27, 2019. Answers (1)
- A car of mass 900 kg collided heads on with a truck of mass 4000 kg travelling at 40 m/s.
The car is thrown on the...(Solved)
A car of mass 900 kg collided heads on with a truck of mass 4000 kg travelling at 40 m/s.
The car is thrown on the bonnet of the truck, which continues to move after impact at
10 m/s in its original direction. What was the speed of the car?
Date posted: May 27, 2019. Answers (1)
- A cork of volume 200 cm3 is floating on water. If the density of the cork is 0.25 g/cm3.
Calculate;
(i) the mass of the cork.
(ii)...(Solved)
A cork of volume 200 cm3 is floating on water. If the density of the cork is 0.25 g/cm3.
Calculate;
(i) the mass of the cork.
(ii) the upthrust force on the cork.
(iii) the minimum force required to immerse the cork completely.
Date posted: May 27, 2019. Answers (1)
- In the diagram below determine the weight of the metre rule shown below.(Solved)
In the diagram below determine the weight of the metre rule shown below.
Date posted: May 27, 2019. Answers (1)
- An object of mass, m1 has weight, w1 in air and w2 in water. Explain which of two weights is greater than the other.(Solved)
An object of mass, m1 has weight, w1 in air and w2 in water. Explain which of two weights is greater than the other.
Date posted: May 27, 2019. Answers (1)