Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

Solutions 177

admissible values of s lies between 0 and

(3-1/ 5 )12, whence

< V 3— k

2 m •

1.77. The change in the kinetic energy Wk of the
body as a result of a small displacement As can
be written in the form

A Wk = F As,

where F is the force acting on the body. Therefore,

the force at a certain point of the trajectory is de-

wk

III

A 02

Pr

litt c s A- 1

NCI NMI

tang:4 8 =U \ gag^1

an rec.= 0.5

5

C

A

Fig. 178

fined as the slope of the tangent at the relevant
point of the curve describing the kinetic energy as
a function of displacement in a rectilinear motion.
Using the curve given in the condition of the prob-
lem, we find that (Fig. 178) F c ti —1 N and
R —3 N.
1.78. The amount of liberated heat will be maxi--
mum if the block traverses the maximum distance
relative to the conveyer belt. For this purpose, it
is required that the velocity of the block relative
to the ground in the vicinity of the roller A mus t

2-0771