Page 51 - text book form physics kssm 2020

Chapter 2 Force and Motion I

Formative Practice 2.2
2.2

1. How do you determine
(a) velocity from a graph of displacement against time?
(b) acceleration from a graph of velocity against time?
(c) displacement from a graph of velocity against time?

2. Based on Figure 2.35, describe the motion of the object from O to D.
Velocity, v / m s –1

v C

u A B

O D Time, t / s
t t t t
1 2 3 4
Figure 2.35
3. Figure 2.36 shows Rokiah taking 3 minutes to walk House Sundry shop
to the sundry shop located 400 m to the right of
KEDAI
her house. After 1 minute, she buys an ice cream 400 m
and walks to the playground located 300 m from
the sundry shop in 2 minutes. She sits and rests on
a bench near the playground for 2 minutes. Then, Shortcut 300 m
using a shortcut to return to her house, Rokiah
reaches her house in 2 minutes.
(a) What is the average velocity of the motion of
Rokiah from Bench
(i) house to the sundry shop?
Figure 2.36
(ii) sundry shop to the playground?
(iii) playground to the house?
(b) Calculate Rokiah’s average speed.

–2
4. A car is driven from rest and accelerated at 4 m s for 8 s along a straight road. Th e car
is driven at the constant velocity for 20 s and then its brakes are applied. Th e car reduces
–2
its velocity at the rate of 2 m s till it stops. Sketch a graph of:
(a) acceleration against time
(b) velocity against time
(c) displacement against time

45
45