A – loses heat through evaporation because of large surface area and B – because dull surface is a good emitter of heat.
sharon kalunda answered the question on September 27, 2019 at 08:09
- A body is acted upon by a force of 10N towards the right hand side and 6N towards the left hand side. What is the...(Solved)
A body is acted upon by a force of 10N towards the right hand side and 6N towards the left hand side. What is the resultant force?
Date posted: September 27, 2019. Answers (1)
- The figure below shows a displacement-time graph of a wave. The velocity of the wave is 100m/s.(Solved)
The figure below shows a displacement-time graph of a wave. The velocity of the wave is 100m/s.
Determine;
(i) Amplitude
(ii) Period
(iii) Wave length
(iv) Frequency
Date posted: September 27, 2019. Answers (1)
- A gas occupies a volume of 4000 litres temperature of 370C and normal atmosphere pressure. Determine the new volume of the gas if it is...(Solved)
A gas occupies a volume of 4000 litres temperature of 370C and normal atmosphere pressure. Determine the new volume of the gas if it is heated at constant pressure to a temperature of 670C (normal atmosphere pressure P = 1.01 x 105pa).
Date posted: September 27, 2019. Answers (1)
- A turn table of radius 8cm is rotating at 33 revolutions per second. Determine the linear speed of a point on the circumference of the...(Solved)
A turn table of radius 8cm is rotating at 33 revolutions per second. Determine the linear speed of a point on the circumference of the turn table.
Date posted: September 27, 2019. Answers (1)
- The figure below shows a rectangular block of wood with a hollow section at the position shown. The block is resting on a...(Solved)
The figure below shows a rectangular block of wood with a hollow section at the position shown. The block is resting on a horizontal bench.
State and explain the effects on stability of the block when the hollow section is filled with water.
Date posted: September 27, 2019. Answers (1)
- The figure below shows two identical balloons A and B the balloons were filled with equal amounts of same type of gas. The balloons are...(Solved)
The figure below shows two identical balloons A and B the balloons were filled with equal amounts of same type of gas. The balloons are suspected at distance X1 and X2 from a metal cube filled with boiling water and placed on an insulating material.
a. State the mode by which heat travels from the cubes to the balloons.
b. The face of the cube towards A is bright and shiny and face towards B is dull black. State with reasons the adjustments that should be made on the distances XI and X2 so that the rate of change of temperature in both balloons remains the same
Date posted: September 27, 2019. Answers (1)
- Give a reason why a person may nose bleed after ascending a high mountain.(Solved)
Give a reason why a person may nose bleed after ascending a high mountain.
Date posted: September 27, 2019. Answers (1)
- The figure below shows water placed in a measuring cylinder calibrated in cm3(Solved)
The figure below shows water placed in a measuring cylinder calibrated in cm3
An object of mass 50.1g and density 16.7 g/cm3 is lowered gently in the water.Calculate the new volume level
Date posted: September 27, 2019. Answers (1)
- The figure below shows an arrangement of capacitors to a 12V d.c. supply.(Solved)
The figure below shows an arrangement of capacitors to a 12V d.c. supply.
Determine
(i) Effective capacitance
(ii) Charge across the 8μF capacitor.
Date posted: September 27, 2019. Answers (1)
- The figure below shows light passing through a transparent block.(Solved)
The figure below shows light passing through a transparent block.
Determine the refractive index of the block.
Date posted: September 27, 2019. Answers (1)
- An electric kettle has an element of resistance 28.8 ohms. It is operating from a 240V main supply. Determine its power rating.(Solved)
An electric kettle has an element of resistance 28.8 ohms. It is operating from a 240V main supply. Determine its power rating.
Date posted: September 27, 2019. Answers (1)
- The figure below shows a wave profile for a wave whose frequency is 2.5HZ.(Solved)
The figure below shows a wave profile for a wave whose frequency is 2.5HZ.
Determine the value of t3
Date posted: September 27, 2019. Answers (1)
- A nail is electrically magnetized, it attracts an increasing number of pins as the magnetizing current increase. After some time it can no longer attract...(Solved)
A nail is electrically magnetized, it attracts an increasing number of pins as the magnetizing current increase. After some time it can no longer attract any more pins. Explain this observation domain theory.
Date posted: September 27, 2019. Answers (1)
- A dry cell is not recharged once used up. However when used well, it can serve one for some time. State the precautions necessary when...(Solved)
A dry cell is not recharged once used up. However when used well, it can serve one for some time. State the precautions necessary when using it other than storing it in dry condition.
Date posted: September 27, 2019. Answers (1)
- Explain why water kept in a porous pot on a hot day remains cooler than that contained in a metallic vessel.(Solved)
Explain why water kept in a porous pot on a hot day remains cooler than that contained in a metallic vessel.
Date posted: September 27, 2019. Answers (1)
- A stone of mass 4kg is thrown upwards with a kinetic energy of 240J. Neglecting air resistance,calculate the height to which it will rise. (Take...(Solved)
A stone of mass 4kg is thrown upwards with a kinetic energy of 240J. Neglecting air resistance,calculate the height to which it will rise. (Take g = 10N/kg)
Date posted: September 27, 2019. Answers (1)
- The figure below shows a pulley system for lifting heavy objects.(Solved)
The figure below shows a pulley system for lifting heavy objects.
(i) State the velocity ratio of the pulley system.
(ii) If the efficiency of the machine is 75%, calculate the mechanical advantage of the system.
(iii) Determine the effort applied
Date posted: September 27, 2019. Answers (1)
- Define a machine.(Solved)
Define a machine.
Date posted: September 27, 2019. Answers (1)
- The figure below shows the starting of motion of two arrows 10M above the ground. Both arrows were shot with initial velocity of 20m/s, from...(Solved)
The figure below shows the starting of motion of two arrows 10M above the ground. Both arrows were shot with initial velocity of 20m/s, from one point and at the same instant.
(i) Determine the total height reached by the arrow shot vertically.
(ii) Calculate the time of flight taken by the arrow shot horizontally as it strikes the ground.
(iii) Calculate the horizontal distance covered by the arrow shot horizontally as it strikes the ground.
Date posted: September 26, 2019. Answers (1)
- A turntable of radius 10cm is rotating at 43 revolutions per second. Determine the linear speed of a point on the circumference of the turntable.(Solved)
A turntable of radius 10cm is rotating at 43 revolutions per second. Determine the linear speed of a point on the circumference of the turntable.
Date posted: September 26, 2019. Answers (1)