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

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.