Question

A screw jack having 5 mm pitch and has 300 mm as diameter of effort wheel is used to lift a load of 80 kN. Find V.R. and effort required it efficiency of machine is
40%.
c)

Answer 1

Answer:

nope

Explanation:

naah. nope

Answer 2

Answer:

Velocity ratio = 188.4

Efficiency = 29.19%

Explanation:

Pitch of screw jack, p = 5 mm = 5 × 10⁻³m

Diameter of wheel, d = 300 mm = 0.3 m

Radius, r = diameter/2

Radius = 0.3/2 = 0.15 m

Effort, E = 40 N

Load, L = 2200 N

Velocity ratio, V.R = ?

Efficiency, η = ?

$V.R = \frac{2\pi r}{p}$

$V.R = \frac{2 * 3.14 * 0.15}{5 * 10^{-3} }$

V.R = 188.4

Mechanical advantage,

$M.A =\frac{Load}{Effort}$

$M.A = \frac{2200}{40}$

M.A = 55

Now/

$Efficiency = \frac{M.A}{V.R} * 100$. = $\frac{55}{188.4} * 100$ = 29.19 %

RESULT: Velocity ratio = 188.4 

              Efficiency = 29.19%