Efficiency is the ratio of work output to work input expressed as a percentage
johnmulu answered the question on February 14, 2017 at 13:08
- A certain machine uses an effort of 400 N to raise a load of 60 0N. If the efficiency of the machine is 75%, determine its velocity ratio(Solved)
A certain machine uses an effort of 400 N to raise a load of 600N. If the efficiency of the machine is 75%, determine its velocity ratio.
Date posted: February 14, 2017. Answers (1)
- A crane lift a load of 2000 kg through a vertical distance of 3.0 m in 6 seconds. Determine the (i) Work done(Solved)
A crane lift a load of 2000 kg through a vertical distance of 3.o m in 6 seconds.Determine the:
i) Work done
ii) Power development by the crane
iii) Efficiency of the crane given that it is operated by an electric motor rated 12.5 KW.
Date posted: February 14, 2017. Answers (1)
- A certain machine raises 2.0 tonnes of water through 22 metres. If the efficiency of the machine is 80%, how much work is done on the machine? (Solved)
A certain machine raises 2.0 tonnes of water through 22 metres. If the efficiency of the machine is 80%, how much work is done on the machine?
Date posted: February 14, 2017. Answers (1)
- If a load on 100 N is raised by applying an effort of 28 N, determine the efficiency of the system(Solved)
If a load on 100 N is raised by applying an effort of 28 N, determine the efficiency of the system.
Date posted: February 14, 2017. Answers (1)
- A body of mass M is allowed to slide down an inclined plane. State two factors that affects its final velocity at the bottom of the incline.(Solved)
A body of mass M is allowed to slide down an inclined plane. State two factors that affects its final velocity at the bottom of the incline.
Date posted: February 14, 2017. Answers (1)
- State the reason why the amplitude of a simple pendulum decrease with time(Solved)
State the reason why the amplitude of a simple pendulum decrease with time.
Date posted: February 14, 2017. Answers (1)
- Name a device used to convert light energy directly into electrical energy(Solved)
Name a device used to convert light energy directly into electrical energy.
Date posted: February 14, 2017. Answers (1)
- A horizontal force of 12 N is applied on a wooden block of mass 2 kg placed on a horizontal surface. It causes the block to accelerate at 5 ms-2(Solved)
A horizontal force of 12N is applied on a wooden block of mass 2 kg placed on a horizontal surface. It causes the block to accelerate at 5 ms-2. Determine the frictional force between the block and the surface.
Date posted: February 14, 2017. Answers (1)
- A student pulls a block of wood along a horizontal surface by applying a constant force. State the reason why the block moves at a constant velocity(Solved)
A student pulls a block of wood along a horizontal surface by applying a constant force. State the reason why the block moves at a constant velocity.
Date posted: February 14, 2017. Answers (1)
- A car of mass 30 kg is pushed along a horizontal path by horizontal force of 8 N and moves with a constant velocity.(Solved)
A car of mass 30 kg is pushed along a horizontal path by horizontal force of 8 N and moves with a constant velocity. The force is then increased to 14N. Determine:
a) The resistance to the motion of the cart;
b) The acceleration of the cart.
Date posted: February 14, 2017. Answers (1)
- State Newton's second law of motion(Solved)
State Newton's second law of motion.
Date posted: February 14, 2017. Answers (1)
- A footballer kicks a ball of mass 0.6 kg initially at rest using a force of 720N. If the foot was in contact with the ball for 0.1 seconds, what was the takeoff speed of the ball?(Solved)
A footballer kicks a ball of mass 0.6 kg initially at rest using a force of 720N. If the foot was in contact with the ball for 0.1 seconds, what was the takeoff speed of the ball?
Date posted: February 14, 2017. Answers (1)
- A trolley is moving at a uniform speed along a track. A piece of plasticine is dropped on the trolley and sticks on it. Explain why the trolley slows down(Solved)
A trolley is moving at a uniform speed along a track. A piece of plasticine is dropped on the trolley and sticks on it. Explain why the trolley slows down.
Date posted: February 14, 2017. Answers (1)
- A high jumper usually lands on thick soft mattress. Explain how the mattress helps in reducing the force of impact(Solved)
A high jumper usually lands on thick soft mattress. Explain how the mattress helps in reducing the force of impact.
Date posted: February 14, 2017. Answers (1)
- An industrial trolley of mass 20 kg carrying a mass of 50 kg is acted on by a constant force. The trolley moves along a horizontal smooth surface with an acceleration of 0.5ms-2(Solved)
An industrial trolley of mass 20 kg carrying a mass of 50 kg is acted on by a constant force. The trolley moves along a horizontal smooth surface with an acceleration of 0.5 ms-2. Determine the acceleration of the trolley after the mass falls off.
Date posted: February 14, 2017. Answers (1)
- A gun is fired vertically upwards from the top of an open truck moving horizontally, uniform velocity of 50ms-1. The bullet achieves a maximum height of 45 m(Solved)
A gun is fired vertically upwards from the top of an open truck moving horizontally, uniform velocity of 50ms-1. The bullet achieves a maximum height of 45 m.
i) State with reason whether or not the bullet will land on the truck
ii) Calculate the distance covered by the truck just before the bullet reaches the level from which it was fired. (Use g = 10 ms-2)
Date posted: February 14, 2017. Answers (1)
- A trolley is moving at constant speed in friction compensated track. Some plasticine is dropped on the trolley and sticks on it. State with a reason what is observed about the motion of the trolley.(Solved)
A trolley is moving at constant speed in friction compensated track. Some plasticine is dropped on the trolley and sticks on it. State with a reason what is observed about the motion of the trolley.
Date posted: February 14, 2017. Answers (1)
- State Newton's first law of motion(Solved)
State Newton's first law of motion.
Date posted: February 14, 2017. Answers (1)
- A nail at the bottom of a beaker containing glycerine appears to be 6.8 cm below the surface of glycerine. Determine the height of the column of glycerine in the beaker(Solved)
A nail at the bottom of a beaker containing glycerine appears to be 6.8 cm below the surface of glycerine. Determine the height of the column of glycerine in the beaker. (Take the refractive index of glycerine as 1.47)
Date posted: February 14, 2017. Answers (1)
- A water wave of wavelength 18 mm is incident on a boundary of shallow water at right angles. If the wavelength in the shallow end is 14.4 mm(Solved)
A water wave of wavelength 18 mm is incident on a boundary of shallow water at right angles. If the wavelength in the shallow end is 14.4 mm, Determine the refractive index of water for a wave moving from the deep to the shallow end.
Date posted: February 14, 2017. Answers (1)