Question

Kinematics
2.25
72. A car A has just overtaken car B which is moving in
the same direction as A. Given below are few cases
76. A boy kicks a football horizontally from the roof of a
explaining the motion of the cars at that instant.
building of height 10 m. If the line joining the initial
Identify the given cases as cases that are necessarily
position of the football and the point where it hits
true, cases that can be true only under certain condi-
the ground make an angle of 45° with the ground,
tions and cases that are necessarily false.
then find the displacement of the football.
(a) The car A is accelerating and car B is decelerating.
77. A rod of length 2 m starts to roll on a horizontal
(b) The car is decelerating and car B is accelerating.
surface as shown in figure. At the same time an ant
starts moving from one end (A) of the rod to other
(c) Both cars are accelerating.
and when the rod rolls through a distance 10 m the
(d) Both cars are decelerating.
ant reaches the other end (B). Calculate the distance
(e) Both cars are moving with uniform velocity.
and displacement of the ant
(f) Car A is moving with uniform velocity and car
(a) with respect to the rod.
B is accelerating.
(b) with respect to the ground.
(g) Instantaneous speed of car A is less than that of
car B.
2 m
B
(h) Instantaneous speed of car B is less than that of
O
A
car A.
10 m
73. Find the initial velocity and acceleration of a body
if the distance traveled by that body in nth second is
(5.96 + 0.08n) m.
A
B
Directions for questions 74 to 78:
Application Based Questions
74. A race horse runs straight north and covers a dis-
tance of 12 m, then turns east and travels a distance of
5 m. Draw the diagram showing the displacements
and from the diagram, calculate the net displacement
of the horse.
78. A bird sitting on a tree top at a height of
5 m from the ground, picks up sticks lying on
the ground to build a nest on the tree top. It
starts picking up the sticks at 7:00 a.m. and ends
up at 7:10 a.m. During this interval it makes
5 trips up and down. Find the average speed and
average velocity of the bird.
75. A crow picks up pebbles and puts them into a pot
which are 10 m away from the pot. In doing so, it
makes 5 trips within 80 seconds. What is the average
speed of the crow?​

Answer 1

solutions are in attachment. mark it as brainliest