Here is a realistic short test. Try solving it in 30 minutes.
1. (Unit conversion - 5 pts)
Express 250 cm² in m².
Answer: ( 0.025 , m^2 )
2. (Uniform motion - 10 pts)
A cyclist travels 15 km in 45 minutes. Calculate her average speed in m/s.
Answer: ( 15 , km = 15000 , m ), ( 45 , min = 2700 , s ). ( v = 15000/2700 \approx 5.56 , m/s )
3. (Accelerated motion - 15 pts)
A train traveling at 30 m/s applies brakes and decelerates uniformly at -2 m/s² until it stops.
a) How long does it take to stop?
b) How far does it travel during braking?
Answers: a) ( t = (0 – 30)/(-2) = 15 , s ) b) ( s = 30·15 + 0.5·(-2)·15² = 450 – 225 = 225 , m ) fizika 1 letnik gimnazije test
4. (Newton’s second law - 10 pts)
A 4 kg box is pulled horizontally with a force of 20 N. Friction is 8 N. Calculate acceleration.
Answer: ( F_net = 20 – 8 = 12 , N ). ( a = F_net/m = 12/4 = 3 , m/s² )
5. (Graph interpretation - 10 pts)
Describe the motion of an object whose v-t graph shows: constant positive slope from t=0 to t=5 s, then horizontal line from t=5 to t=10 s.
Answer: From 0–5 s: uniformly accelerated motion; from 5–10 s: constant velocity motion.
Graphs to master:
| Concept | Formula | |---------|---------| | Average speed | (v = \fracst) | | Acceleration | (a = \frac\Delta v\Delta t) | | Uniform motion | (x = x_0 + vt) | | Accelerated motion | (v = v_0 + at,\quad x = x_0 + v_0 t + \frac12 a t^2) | | Newton’s 2nd law | (F = ma) | | Weight | (F_g = mg) | | Friction | (F_tr = \mu F_N) | | Work | (W = F \Delta x) | | Kinetic energy | (E_k = \frac12 m v^2) | | Potential energy | (E_p = m g h) | | Power | (P = \fracWt = F v) | | Pressure | (p = F/A) | | Hydrostatic pressure | (p = \rho g h) |
This is the largest section. Focus on uniform motion and uniformly accelerated motion.
Classic test problem: A car starts from rest and accelerates at 2 m/s² for 5 seconds. How far does it travel? (Answer: 25 m). Here is a realistic short test
Izvedite preprost poskus: merjenje prostega padajočega predmeta (npr. majhen kovinski kroglici) z uporabo mobilnega telefona za merjenje časa.
Navodila:
Poročilo naj vsebuje: cilj, oprema, postopek, meritve (tabele), izračune, napake in zaključek. Classic test problem: A car starts from rest
| Concept | Formula |
|---------|---------|
| Average speed | ( v = \frac\Delta s\Delta t ) |
| Acceleration | ( a = \frac\Delta v\Delta t ) |
| Equations of motion (uniform acceleration) | ( v = v_0 + a t )
( s = v_0 t + \frac12 a t^2 )
( v^2 = v_0^2 + 2 a s ) |
| Newton’s second law | ( F = m a ) |
| Weight | ( F_g = m g ) |
| Work | ( W = F \cdot d \cdot \cos\theta ) |
| Kinetic energy | ( E_k = \frac12 m v^2 ) |
| Gravitational potential energy | ( E_p = m g h ) |
| Power | ( P = \fracWt ) |
| Momentum | ( p = m v ) |
| Impulse | ( J = F \cdot \Delta t = \Delta p ) |