In A2/A-Level Mathematics, we discussed the equation of motion in part 1 and now we will have some examples.
Example #1
A car starts from rest and accelerates at 10 ms-1 for 3 secs. What is the maximum speed it attains?
Example #2
A car travelling at 25 ms-1 starts to decelerate at 5 ms-2. How long will it take for the car to come to rest?
Example #3
A car travelling at 20 ms-1 decelerates at 5 ms-2. How far will the car travel before stopping?
Example #4
A car travelling at 30 ms-1 accelerates at 5 ms-2 for 8 secs. How far did the car travel during the period of acceleration?
Vertical motion under gravity
In A2/A-Level Mathematics, these problems concern a particle projected vertically upwards and falling 'under gravity'. In these types of problem it is assumed that:
air resistance is minimal
displacement & velocity are positive(+) upwards & negative(-)downwards
acceleration(g) always acts downwards and is therefore negative(-)
acceleration due to gravity(g) is a constant
Example #1
A stone is thrown vertically upwards at 15 ms-1.
i) what is the maximum height attained?
ii) how long is the stone in the air before hitting the ground?
i) (Assume g = 9.8 ms-2. Both answers to 2 d.p.)
ii)
Example #2
A boy throws a stone vertically down a well at 12 ms-1. If he hears the stone hit the water 3 secs. later,
i) how deep is the well?
ii) what is the speed of the stone when it hits the water?
i)
(Assume g = 9.8 ms-2. Both answers to 1 d.p.)
ii)
That's the end of the topic in A2/A-Level Mathematics.