4 The approximate velocity-time graph for a car on a 5-hour journey is shown in Figure 3.8. (There is a very quick driver
change midway to prevent driving fatiguel)
a State in which of the regions OA, AB, BC, CD, DE the
car is (i) accelerating, (ii) decelerating, (iii) travelling
with uniform velocity
b Calculate the value of the acceleration, deceleration or
constant velocity in each region.
c What is the distance travelled over each region?
d What is the total distance travelled?
e Calculate the average velocity for the whole journey.
C D
100
А
B
80
speed/kmh)
60
40
20
o
E
o
0
4
5
2 3
time/hours

answer; (arch); good luck

0.3x0.21x0.08kg=mass 1 sheet

mass 500 = 500xmass 1

volume pile = 0.3x0.2x0.048

density=mass/volume= 500xmass 1/0.3x0.2x0.048

v patient student

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.