#### Βiggest velocity / kinetic energy

The kinetic energy of an object is given by the equation :$K=\frac{1}{2}mv²$. If two objects with mass $3 kg$ and $12 kg$ have: a) the same kinetic energy, which object has the biggest velocity? b) the same velocity, which object have the biggest energy?

Modeling
9

#### Find the area

A farmer has divided his field into 10 isembadic squares and in each one sows a different kind of vegetable. A. Can you find the function that expresses the area of the field? B. Ιf each square has a side of 40m find the area of the field.

Modeling
10

#### Find coefficient

Find $a$ if the graph of quadratic function$f(x) = (2a+3)x^2$ is passing through the point $A(3,45)$

Reasoning
9

#### A bag full of coins

Peter finds a bag with 50 coins inside. The bag only contains coins of 2 cents and 5 cents (of Euro €). If the total value of the coins is 1.81€, how many more 5 cents coins are there than 2 cents coins?

# Linear equations

Modeling
8

#### Linear equation with denominator.

Find the value of x solving this equation with denominators.

# Linear equations

Training
7

#### Linear equation with brackets.

Find the value of x solving this equation with a bracket.

# Linear equations

Training
7