Question

Help me to solve this..​

Answer 1

We know E = h ν

h = 6.626 x 10⁻³⁴ J Hz⁻¹

given  ν₀ = 7.0 x 10¹⁴ s⁻¹   ;   ν = 1.0 x 10¹⁵ s⁻¹ .

total energy provided = (threshold enegry) + (kinetic energy)

              ⇒  hν = hν₀ + KE

  ⇒ h x 1.0 x 10¹⁵ s⁻¹  = h x 7.0 x 10¹⁴ s⁻¹  +  KE

   ⇒  h x ( 1.0 x 10¹⁵ s⁻¹ - 7.0 x 10¹⁴ s⁻¹ )   = KE

  ⇒   6.626 x 10⁻³⁴ J Hz⁻¹ x 3 x 10¹⁴ Hz  =  KE

   ⇒   KE = 1.9878 x 10⁻¹⁹ J

Hope this helps you ✌️✌️☘️☘️.

Answer 2

Answer:

Given that,

vo=7.0×1014s−1

v=1.0×1015s−1

As we know, hv=hv0+21mv2

i.e. h(v−v0)=K.E.

∴K.E.=(6.626×10−34)×(1.0×1015−7.0×1014)=6.626×10−34×1014(10−7)

∴K.E=19.878×10−20J

Explanation:

please pinky iam sorry