Answer:
94
Explanation:
f = 2.57 x 10^13 Hz
E = 10 eV = 10 x 1.6 x 10^-19 J = 1.6 x 10^-18 J
Energy of each photon = h f
Where, h is Plank's constant
Energy of each photon = 6.63 x 10^-34 x 2.57 x 10^13 = 1.7 x 10^-20 J
Number of photons = Total energy / energy of one photon
N = (1.6 x 10^-18) / (1.7 x 10^-20) = 94.11 = 94
by momentum conservation
64× v=42×3.11
v=2.04m/s
B. coefficient
i dont have to explain right?
0.02 m/s^2
change in velocity= 4.5m/s - 2.3m/s = 2.2 m/s
acceleration= change in velocity/change in time
acceleration= 2.2/120= 0.0183
= 0.02 (to 2 significant figures)
