Explanation:
The scanner records the time from when a ultrasound wave is emitted to when its reflection is received. A technician calculates the depth of the reflection using the equation as :

The distance covered by ultrasonic wave when it was emitted and gets reflected is 2d. Speed is given by :

d is distance and t is time
Here, d = 2d
So, the factor of (1/2) is used because the distance covered by the wave is 2 times when it was emitted and received.
Correct Question:-
A jack exerts a vertical force of 4.5 × 10³
newtons to raise a car 0.25 meter. How much
work is done by the jack?

Given :-



To find:-


Solution:-
we know :-


So:-



























The correct answer is B) One atom of calcium and two atoms of chlorine. I just had the same question on my 9th grade science test today. I hope I didn't give the answer to you too late and I hope it helps you out
Answer:
"caffeine" both products contain this compound
Answer:
1 eV
Explanation:
Given:
Work function, ∅ = 2.00 eV
Kinetic energy of the ejected of the electron, K.E = 4.0 eV
Now,
using the photoelectric equation
, we have
Energy of the photon (E) = ∅ + K.E
also,
E = hc/λ
where, h is plank's constant
c is the speed of the light
λ is the wavelength
thus, we have
hc/λ = 2 + 4 = 6 eV
Energy of photon = 6eV
Now,
for the second case
λ' = 2λ
when Wavelength is doubled , E is halved
thus,
E' = hc/λ'
or
E' = hc/2λ
or
E' = E/2 = 6/2 = 3 eV
also,
E' = ∅ + KE
'
thus on substituting the values,
3 = 2 + KE'
or
KE' = 1 eV
Hence, the maximum kinetic energy for the second case is 1 eV