A Screw Jack With Pitch Of 0.2cm And Handle Of Length 50cm Is Used To Lift A Car Of Weight 12000N the efficiency of screw is 30%, what is its velocity ratio
Answer
To calculate the velocity ratio of a screw jack, we need to know the pitch of the screw and the length of the handle.
Given:
Pitch (P) = 0.2 cm (or 0.002 m)
Handle Length (L) = 50 cm (or 0.5 m)
Efficiency (η) = 30% (or 0.30)
The efficiency (η) formula for a screw jack is given by:
η = (Output/Input) × 100%
We can rearrange this formula to solve for the velocity ratio (VR):
VR = Output/Input
Now let's determine the output and input:
Output:
The output is the weight being lifted by the screw jack, which is the weight of the car.
Weight (W) = 12000 N
Input:
The input is the effort applied to the handle of the screw jack.
Effort (E) = ? (unknown)
Input and Output are related to the velocity ratio (VR) through the following equation:
VR = (Output/Input) = (L/P)
Now, let's solve for the velocity ratio:
VR = (L/P) = (0.5 m) / (0.002 m) = 250
Therefore, the velocity ratio of the screw jack is 250.