a scrow jack whose pitch is 2mm is used to raise a motor car of mass 900kg through a height of 200cm the length of the tommy bar of the jack is 40cm and if the jack is 60% efficience.calculate;
(a)velocity ratio(b)machanical advantage(c)calculate the effort (d)workdone by the effort(g=10m/s)
30
20
40
bola
Please help me to solve that physics question and please it should be step by step so that I will understand it
Am waiting oooo
To answer these questions, we need to make use of the formulas and definitions related to screws, including the screw jack. Let me guide you through the process step by step:
(a) Velocity ratio:
The velocity ratio is defined as the ratio of the distance moved by the effort (or load) to the distance moved by the handle (or tommy bar) of the screw jack. In this case, the pitch of the screw is given as 2mm, and the length of the tommy bar is 40cm.
To calculate the velocity ratio, we need to divide the distance moved by the load by the distance moved by the handle. The distance moved by the load is the height to which the motor car is raised, which is given as 200cm. The distance moved by the handle is the circumference of the screw, which is equal to the pitch times the number of turns made by the screw jack.
The number of turns is equal to the distance moved by the handle divided by the pitch. Converting the measurements to the same unit (cm) gives us:
Number of turns = (40 cm) / (2 mm) = (40 cm) / (0.2 cm) = 200 turns
Now we can calculate the distance moved by the handle:
Distance moved by the handle = (pitch) * (number of turns) = (2 mm) * (200 turns) = 400 mm
Converting the distance moved by the handle to cm gives us:
Distance moved by the handle = 40 cm
Now we can calculate the velocity ratio:
Velocity ratio = (distance moved by the load) / (distance moved by the handle) = (200 cm) / (40 cm) = 5
So, the velocity ratio is 5.
(b) Mechanical Advantage:
The mechanical advantage is defined as the ratio of the load to the effort. In this case, the load is the weight of the motor car, which is given as 900 kg, and the effort is the force applied at the end of the tommy bar.
To calculate the mechanical advantage, we need to divide the load by the effort. The effort can be calculated using the formula:
Effort = (load) / (mechanical advantage)
Given that the efficiency of the jack is 60% (or 0.6), the mechanical advantage is related to the efficiency by the formula:
Mechanical advantage = (load) / (efficiency)
Plugging in the values we have:
Mechanical advantage = (900 kg) / (0.6) = 1500
So, the mechanical advantage is 1500.
(c) Effort:
We can use the mechanical advantage formula to calculate the effort. Rearranging the formula, we have:
Effort = (load) / (mechanical advantage) = (900 kg) / (1500) = 0.6 kg
So, the effort is 0.6 kg.
(d) Work done by the effort:
The work done by the effort can be calculated using the formula:
Work done = (effort) * (distance moved by the handle)
We have already calculated the distance moved by the handle as 40 cm. Converting it to meters gives us:
Distance moved by the handle = 0.4 m
Now we can calculate the work done by the effort:
Work done = (0.6 kg) * (0.4 m) = 0.24 Joules
So, the work done by the effort is 0.24 Joules.