K.C.S.E Physics Q & A - MODEL 2016PP1QN16

K.C.S.E Physics Q & A - MODEL 2016PP1QN16

(a)Define the term velocity ratio of a machine.
(b) Fig. 12 shows part of a hydraulic press. The plunger is the position where effort is applied while the Ram piston is the position where load is applied. The plunger has cross-section area, a m² while the Ram piston has cross-section area, A m².

When the plunger moves down a distance d the Ram piston moves up a distance D.
Derive an impression for the velocity ratio (V.R) in terms of A and a
c) A machine of velocity ratio 45, overcomes a load of 4.5 x 10³N when an effort of 135N is applied. Determine:
(i)The mechanical advantage of the machine;
(ii) Efficiency of the machine;
(iii) The percentage of the work that goes to waste.

answers

​(a)It is the ratio of distance moved by effort to distance moved by load