Answer:
1411.8 N/m
Explanation:
From Hooke's law;
F= Ke
Where
F= force on the spring
K= force constant
e = extension
But e= 8.50 × 10^-2m
F= weight = 12.0 kg × 10 = 120 N
K = F/e = 120/8.50 × 10^-2
K= 1411.8 N/m
Answer:
The velocity of the student has after throwing the book is 0.0345 m/s.
Explanation:
Given that,
Mass of book =1.25 kg
Combined mass = 112 kg
Velocity of book = 3.61 m/s
Angle = 31°
We need to calculate the magnitude of the velocity of the student has after throwing the book
Using conservation of momentum along horizontal direction


Put the value into the formula


Hence, The velocity of the student has after throwing the book is 0.0345 m/s.
Hardness, color , and luster.
But since you can pick one, I would say hardness
The energy of a photon is given by

where h is the Planck constant and f is the photon frequency.
We can find the photon's frequency by using the following relationship:

where c is the speed of light and

is the photon's wavelength. By plugging numbers into the equation, we find

And so now we can find the photon energy

We know that 1 Joule corresponds to

So we can convert the photon's energy into electronvolts: