SIMPLE MACHINES
1.
In the certain machine, the
load moves 4 m when effort moves 16 m. An effort of 40 N is used to raise load of
120 N. What is the efficiency of the machine?
2.
A force applied parallel to
an inclined plane is used to raise a load of 500 N through a height of 3.0 m.
The effort moved through a distance of 30 m along the plane.
i)
How much work is done on
the load?
ii) If the efficiency of the inclined plane is 80%, determine the
effort applied.
iii) How much work is done by the effort?
3.
A block and tackle pulley system
has 3 pulleys in the fixed block and 2 in the lower movable block. What load
can be lifted by an effort of 400 N if the efficiency of the system is 60%?
4.
A force of 600 N is used to
move a load up an inclined plane. Given that the slant height and the vertical
height of the plane are 18 m and 3 m respectively. Determine;
i)
The velocity ratio of the
plane.
ii) The mechanical advantage of the plane.
iii) The efficiency of the plane.
5.
A crane lifts a load of
1000 Kg through a vertical distance of 150 cm. Determine the work done by the
crane against gravity.
6.
(a)Explain what is lever
and give the essential features of the lever.
(b) A lever system of velocity
ratio 45 overcomes a load of 4500 N when an effort of 125 is applied. Find
i)
The mechanical advantage of
the lever.
ii) The efficiency of the lever.
7.
(a) Give four examples of
simple machines.
(b) A pulley system has three
wheels on the lower block and three on the upper block. The system is used to
raise a load of 600 N.
i)
Draw a sketch diagram to
show the arrangement of the pulley system.
ii) Determine the velocity ratio (V.R) of the system.
iii) If the efficiency of the system is 90% determine effort applied
in raising the 600 N load.
8.
A wheel and axle of
efficiency 80% is used to raise a load of 2000 N. If the radius of the wheel is
50 cm, and that of the axle is 2 cm, calculate
i)
The velocity ratio
ii) Mechanical Advantage of machine
iii) The effort required to overcome the load
9.
A screw jack with a pitch
of 0.2 cm and a handle of length 50 cm is used to lift a car of weight 1.2 x 104
N. If the efficiency of the screw is 30%, find:
i)
The velocity ratio
ii) Mechanical Advantage of the machine
iii) The effort required to raise the car
10.
A loaded wheelbarrow of
weight 800 N is pushed up an inclined plane by a force of 150 N parallel to the
plane. If the plane rises by 50 cm for every 400 cm distance measured along the
plane, find;
i)
The velocity ratio,
ii) Mechanical advantage
iii) Efficiency of the plane.
No comments:
Post a Comment