<span>First of all, the maximum speed occurs when the object passes through the
equilibrium position
The kinetic energy when the object has this max speed is
K= 1/2 * mass * (1.25 m/s)^2
The potential energy in the spring when the speed is equal to zero
U= 1/2 * k * xmax^2
The maximun force of the spring is
mass*acceleration = k*xmax
m * 6.89 m/s2 = k * xmax
xmax = 6.89* m / k
0.5 * m * 1.56 = 0.5 * k * xmax^2
</span>m * 1.56 = k * (<span>6.89* m / k )^2 </span>
<span>
1.56 m = 47.47 m^2 / k
m/k = 0.032862
period = 2 *pi*sqrt[m/k]
= 2 pi </span><span>sqrt [ </span><span>0.032862]
= 1.139 s
A fourth of the period elapses between the instants of max acceleration and maximum speed
= 1/4* period
= 1/4 * </span><span><span>1.139 s </span>
= 0.284s </span>
Answer:
Number of photons travel through pin hole=
Explanation:
First we will calculate the energy of single photon using below formula:

Where :
h is plank's constant with value 
c is the speed of light whch is
λ is the wave length = 532nm

E=
J
Number of photons emitted per second:

Number of photons emitted per second=
=
Where:
A-hole is area of hole
A-beam is area of beam
d-hole is diameter of hole
d-beam is diameter if beam
=
=
=
Number of photons travel through pin hole=
Number of photons travel through pin hole=
The weight of the load is (mass) x (gravity).
The work done to lift it is (weight) x (distance) = (mass) x (gravity) x (distance)
The power is (work)/(time) =
(mass) x (gravity) x (distance) / (time) =
(500 kg) x (9.8 m/s²) x (12 m) / (1 sec) =
(500 x 9.8 x 12 / 1) (kg-m / sec²) (m) / (sec) =
(500 x 9.8 x 12 / 1) newton - meter / sec =
(500 x 9.8 x 12 / 1) joule / sec =
58,800 watts
= <em>58.8 kW</em>
= about 78.8 horsepower