A boy throws rocks with an initial velocity of 12 m/s [down] from a 20 m bridge into a river. Consider the river to be at a height of 0 m. Draw a velocity-time and position-time graph. Use up as positive and ignore air resistance.

a. 48 salads were bought on Wednesday

b. 42 chickens were bought on Thursday

c. 39 cheese were bought on Friday

Step-by-step explanation:

Given

------- M -- T - W -- T -- F−−−−−−−M−−T−W−−T−−F

Cheese ----- 50 -- 45 - 52 - 47 --39

Salad -------- 61 -- 44 - - 48 - 38 -- 51

Chicken ---- 53 -- 46 - - 39 - 42 -- 52

First, it should be noted that the horizontal data represent the row while the vertical data represent the column.

Having said that, the solution is as follows:

Solving (a): Second Row, Third column

The data at the second row are:

------- M -- T - W -- T -- F−−−−−−−M−−T−W−−T−−F

Salad -------- 61 -- 44 - - 48 - 38 -- 51

The data at the third column is then limited to:

------------------W

Salad -------- 48

So the number at this position implies that: 48 salads were bought on Wednesday

Solving (b): Third Row, Fourth column

The data at the second row are:

------- M -- T - W -- T -- F−−−−−−−M−−T−W−−T−−F

Chicken ---- 53 -- 46 - - 39 - 42 -- 52

The data at the fourth column is then limited to:

------------------- T

Chicken ---- 42

So the number at this position implies that: 42 chickens were bought on Thursday

Solving (c): First Row, Fifth column

The data at the first row are:

------- M -- T - W -- T -- F−−−−−−−M−−T−W−−T−−F

Cheese ----- 50 -- 45 - 52 - 47 --39

The data at the fifth column is then limited to:

------------------F

Cheese ----- 39

So the number at this position implies that: 39 cheese were bought on Friday