Answer:
9.801 m/s²
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity = 39 ft/s
s = Displacement = 720 cm = 7.2 m
a = Acceleration
Converting to m/s

Equation of motion

Acceleration of the ball is 9.801 m/s²
Answer:
Deep ocean trenches, volcanoes, island arcs, submarine mountain ranges, and fault lines.
Explanation:
B is the answer! Because no one would be pushing the rock all the way down the hill it would just go down by itself by rolling!!
Hope i helped plz mark as brainlist and 5 star'!
Answer:
f = 7.9487 10¹³ Hz
Explanation:
The photoelectric effect was correctly explained by Einstein assuming that the radiation is composed of photons, which behave like particles.
hf = K + Ф
It indicates the frequency and the kinetic energy, let's look for the work function
Ф = hf - K
let's reduce the magnitudes to the SI system
K = 0.332 eV (1.6 10⁻¹⁹ J / 1 eV) = 0.5312 10⁻⁻¹⁹ J
let's calculate
Ф = 6.63 10⁻⁻³⁴ 6.64 10¹¹ - 0.5312 10⁻¹⁹
Ф = 4.40 10⁻²² - 0.5312 10⁻¹⁹
Ф = 5.27 10⁻²⁰ J
for the minimum frequency that produces photoelectrons, the kinetic energy is zero
hf = Ф
f = Ф / h
f = 5.27 10⁻²⁰ / 6.63 10⁻³⁴
f = 7.9487 10¹³ Hz