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
Answer:
Explanation:
Newton's 2 nd law of motion tells that when equal torque is applied on object having higher moment of inertia , it will rotate slower .
Moment of inertia of boiled egg is higher because the whole egg rotates as s solid unit . Hence it will rotate slower or it rolls slower on an inclined surface .
In this way by applying Newton's law , we can identify raw or boiled egg .
Answer:
Because it has more mass
Explanation:
To understand this, think about the equation of kinetic energy
KE =
m 
Kinetic energy depends on both the velocity (v) as well as the mass (m).
Because a lorry is bigger and heavier than a car, it will have more mass. With more mass, at the same velocity the lorry with have more kinetic energy.
Answer:

Explanation:
Given that
Radius of track = R
Radius of ball = r
The ball can be treated as solid sphere, so
The moment of inertia of ball

When the ball reach at the lowest position then it will have both angular and linear speed.
Condition for rolling without slipping v= ωr
Form energy conservation

v= ωr





