Zdzisław moved a package lying on the floor over the distance of 3 m. Then he did the workworkwork of 0,6 kJ. Calculate the value of the forceforceforce that he worked with (assume that it had the horizontal direction and a constant value).

The SIndeks dolny 1₁ engine did the workworkwork of 120 J in 20 s, and the SIndeks dolny 2₂ engine did the work of 1,8 kJ in 5 minutes. Which one has more powerpowerpower?

Calculate the power of the radio which consumes 0,6 kWh of energyenergyenergy in 3 hours (1 kWh = 1000 W · 3600 s = 3600000 J).

Calculate the kinetic energyenergyenergy of a body weighing 2 kg, which moves at the speed of 5 $\frac{{\displaystyle m}}{s}$ .

What is the mass of the body which was moved to the height of 5 m and has the potential energypotential energypotential energy of 100 J?

What work will Staś do while moving the table using the force of 60 N over the distance of 5 m?

What was the power of the worker who did work of 3600 J in 10 minutes?

What workworkwork will the 1,2 kW engine do if it works for 120 seconds?

A brick weighing 2 kg is on the roof of a five‑story house. In this building, each flat has the height of 2,5 m. Calculate:

a) the value of the work which was done while lifting the brick to this height,

b) its potential energy relative to the Earth,

c) the value of the kinetic energy at the moment of collision with the Earth when it fell freely.

You are standing on the school pitch and throwing the ball upright. Describe in English what changes in the mechanical energy of the ball occur during the entire flight until the fall.