Fizika 7 Razred Zadaci I Rješenja Fixed 【RECOMMENDED ✔】

[ v = \fracst = \frac120 , \textkm2 , \texth = 60 , \textkm/h ] In m/s: [ 60 , \textkm/h = \frac603.6 = 16.67 , \textm/s ] Problem 2 A cyclist rides at 5 m/s for 20 seconds. How far does he go?

[ a = \fracFm = \frac20 , \textN4 , \textkg = 5 , \textm/s^2 ] 3. Density (Gustoća) Key formula: ( \rho = \fracmV ) Unit: ( \textkg/m^3 ) or ( \textg/cm^3 ) Conversion: ( 1 , \textg/cm^3 = 1000 , \textkg/m^3 ) Problem 5 A wooden block has mass 240 g and volume 300 cm³. Calculate density in g/cm³ and kg/m³. fizika 7 razred zadaci i rješenja

[ E_p = m g h = 3 \times 10 \times 4 = 120 , \textJ ] Problem 10 A 2 kg object moves at 3 m/s. Find its kinetic energy. [ v = \fracst = \frac120 , \textkm2

[ s = v \cdot t = 5 , \textm/s \times 20 , \texts = 100 , \textm ] 2. Force (Sila) Key formula: ( F = m \cdot a ) (Newton’s second law) Unit: Newton (N) Weight: ( F_g = m \cdot g ) (( g \approx 9.81 , \textN/kg ), often taken as ( 10 , \textN/kg ) in 7th grade) Problem 3 What is the weight of a 5 kg object? (Use ( g = 10 , \textN/kg )) Density (Gustoća) Key formula: ( \rho = \fracmV

[ F_g = m \cdot g = 5 , \textkg \times 10 , \textN/kg = 50 , \textN ] Problem 4 A force of 20 N acts on a 4 kg object. What is its acceleration?

[ p = \fracFA = \frac500 , \textN0.25 , \textm^2 = 2000 , \textPa ] Problem 8 Calculate the water pressure at 2 m depth. (( \rho_\textwater = 1000 , \textkg/m^3, g = 10 , \textN/kg ))