- Using the pulley system shown below a mass of 10kg is raised 2M by effort of 80N.(Solved)
Using the pulley system shown below a mass of 10kg is raised 2M by effort of 80N.
(i) Calculate the distance the effort moves.
(ii) How much potential energy does the load gain.
(iii) How much work is done by the effort?
(iv) What is the efficiency of these pulleys?
Date posted: September 11, 2019. Answers (1)
- The figure below shows an object of mass 1kg whirled in a vertical circle of radius 0.5m at a uniform speed of 5m/s.(Solved)
The figure below shows an object of mass 1kg whirled in a vertical circle of radius 0.5m at a uniform speed of 5m/s.
(i) Determine:
I the centripetal force on the object.
II the tension in the string when the object is at A.
III the tension in the string when the object is at B.
(ii) The speed of rotation is gradually increased until the string snaps. At what point is the string likely to snap. Explain.
Date posted: September 11, 2019. Answers (1)
- A rock of mass 150kg moving at 10m/s collides with a stationary rock of mass 100kg. They fuse after collision.Determine the
(i) Total momentum before collision....(Solved)
A rock of mass 150kg moving at 10m/s collides with a stationary rock of mass 100kg. They fuse after collision.Determine the
(i) Total momentum before collision.
(ii) Total momentum after collision.
(iii) Their common velocity after collision.
Date posted: September 11, 2019. Answers (1)
- The figure below shows a balloon filled with air.When the mouth is suddenly opened, the balloon moves in the direction shown by the arrow. Explain...(Solved)
The figure below shows a balloon filled with air.When the mouth is suddenly opened, the balloon moves in the direction shown by the arrow. Explain that observation.
Date posted: September 11, 2019. Answers (1)
- Give a reason why the inside of a helmet is lined with sponge.(Solved)
Give a reason why the inside of a helmet is lined with sponge.
Date posted: September 11, 2019. Answers (1)
- State one application of cooling caused by evaporation.(Solved)
State one application of cooling caused by evaporation.
Date posted: September 11, 2019. Answers (1)
- A certain powder of mass 100g was heated in a container by an electric heater rated 100w for some time. The graph below shows the...(Solved)
A certain powder of mass 100g was heated in a container by an electric heater rated 100w for some time. The graph below shows the variation of the temperature of the powder with time.
Use the graph to:
(i) Determine the melting point of the powder
(ii) Determine the quantity of heat supplied by the heater from the time the powder starts to melt to the time it has melted.
(iii) Determine the specific latent heat of fusion of the powder assuming the container absorbs negligible amount of heat.
Date posted: September 11, 2019. Answers (1)
- The figure below represents a block of uniform cross-sectional area 6.0cm² floating on two liquids A and B. The length of the block in each...(Solved)
The figure below represents a block of uniform cross-sectional area 6.0cm² floating on two liquids A and B. The length of the block in each liquid is shown.
Given that the density of liquid A is 800kg/m³ and that of liquid B is 1000kg/m³
determine.
(i) Weight of liquid A displaced.
(ii) Weight of liquid B displaced.
(iii) Density of the block.
Date posted: September 11, 2019. Answers (1)
- The figure below shows two forces F1 and F2 acting on an object.Show on the same figure the resultant force.(Solved)
The figure below shows two forces F1 and F2 acting on an object.Show on the same figure the resultant force.
Date posted: September 11, 2019. Answers (1)
- An aircraft 320m from the ground travelling horizontally at 50m/s releases a bomb. Calculate the horizontal distance covered by the bomb from the point of...(Solved)
An aircraft 320m from the ground travelling horizontally at 50m/s releases a bomb. Calculate the horizontal distance covered by the bomb from the point of release (ignore air resistance and g = 10m/s²).
Date posted: September 11, 2019. Answers (1)
- A cork enclosing steam in a boiler is held down by the system shown below.(Solved)
A cork enclosing steam in a boiler is held down by the system shown below.
If the area of the cork is 20cm², and the force F is 300N, determine the pressure of the steam in the boiler.
Date posted: September 11, 2019. Answers (1)
- The figure below shows a solid sphere with its centre of gravity marked with a dot. The sphere is rolled on a horizontal ground and...(Solved)
The figure below shows a solid sphere with its centre of gravity marked with a dot. The sphere is rolled on a horizontal ground and comes to rest after Some time.Sketch the sphere and mark with a dot the most likely position of the c.o.g after it comes to rest.
Date posted: September 11, 2019. Answers (1)
- The figure below shows water level in limb Q of a glass tube. Indicate the corresponding water levels in limb N, O and P.Explain your...(Solved)
The figure below shows water level in limb Q of a glass tube. Indicate the corresponding water levels in limb N, O and P.Explain your answer.
Date posted: September 11, 2019. Answers (1)
- The figure below shows two identical burning splints. Placed on wood and metal blocks respectively it was observed that when the flame reached the edge...(Solved)
The figure below shows two identical burning splints. Placed on wood and metal blocks respectively it was observed that when the flame reached the edge of the metal block the splint was extinguished while the other on the wooden block continued to burn. Explain this observation.
Date posted: September 11, 2019. Answers (1)
- When washing clothes, it is easier to remove the dirt using some warm water containing soap than cold water. Explain this observation.(Solved)
When washing clothes, it is easier to remove the dirt using some warm water containing soap than cold water. Explain this observation.
Date posted: September 11, 2019. Answers (1)
- The figure below shows the inner parts of a three-pin plug.(Solved)
The figure below shows the inner parts of a three-pin plug.
(i) Identify the pins A and B.
(ii) State the reason why the pin B is normally longer than the other two pins A and C.
Date posted: September 10, 2019. Answers (1)
- State how an increase in thickness affects electrical resistance of a conductor.(Solved)
State how an increase in thickness affects electrical resistance of a conductor.
Date posted: September 10, 2019. Answers (1)
- The figure below shows part of a circuit containing three capacitors.(Solved)
The figure below shows part of a circuit containing three capacitors.
(i) Calculate the effective capacitance between A and B.
(ii) Given that the potential difference (p.d.) across AB is 10V, what is the total charge flowing through the circuit?
Date posted: September 10, 2019. Answers (1)
- State how ‘Hysteresis loss’ can be reduced.(Solved)
State how ‘Hysteresis loss’ can be reduced.
Date posted: September 10, 2019. Answers (1)
- The figure below shows a 12V, 24W lamp operated by a step-down transformer that is connected to a 240V mains supply.(Solved)
The figure below shows a 12V, 24W lamp operated by a step-down transformer that is connected to a 240V mains supply.
(i) Explain what is meant by the term ‗laminated core’ and state its significance in a transformer.
(ii) Calculate the efficiency of the transformer if the current through the primary coil is 0.12 A.
Date posted: September 10, 2019. Answers (1)