Answer:

Explanation:
First of all, let's convert from nanometres to metres, keeping in mind that

So we have:

Now we can convert from metres to centimetres, keeping in mind that

So, we find:

Answer:
The right solution is:
(a) 2.87 eV
(b) 1.4375 eV
Explanation:
Given:
Wavelength,
= 433 nm
Potential difference,
= 1.43 V
Now,
(a)
The energy of photon will be:
E = 
= 
or,
= 
= 
(b)
As we know,
⇒ 
By substituting the values, we get
⇒ 
⇒ 
or,
⇒ 
⇒ 
KE = 1/2mv^2
KE= 1/2(2)(5)^2
KE= 25 J
C. a truck rolling down hill
Answer: 91.4 J
Explanation:
Kinetic energy is the energy possessed by a body due to virtue of its motion.
K.E. = 0.5 m v²
Mass of the continent is given, m = 1.819 × 10²¹ kg
Side of the block of continent, s = 4150 km = 4150000 m
Depth of the block of continent, d = 38 km = 38000 m
(Mass = density × volume
m = 2780 kg/m³× (4150 × 10³ m)²× 38 × 10³ m = 1.819 × 10²¹ kg)
The continent is moving at the rate of, v = 1 cm /year = 0.01 m / 31556926 s = 3.17 × 10⁻¹⁰ m/s
⇒ K.E. = 0.5 × 1.819 × 10²¹ kg × (3.17 × 10⁻¹⁰ m/s)²= 91.4 J
Hence, mass of the continent has 91.4 J of kinetic energy.