Here we can use Newton's II law to find the acceleration of the car
here we know that
as we know that two forces are equal in magnitude but opposite in direction so in order to find net force we need to subtract it
now from above equation
so here option A is correct
Answer:
4.17 m/s
Explanation:
To solve this problem, let's start by analyzing the vertical motion of the pea.
The initial vertical velocity of the pea is
Now we can solve the problem by applying the suvat equation:
where
is the vertical velocity when the pea hits the ceiling
is the acceleration of gravity
s = 1.90 is the distance from the ceiling
Solving for ,
Instead, the horizontal velocity remains constant during the whole motion, and it is given by
Therefore, the speed of the pea when it hits the ceiling is
Answer:
the charge carriers have an energy 2.8 10⁻¹⁹ J
Explanation:
The energy in a diode is conserved so the energy supplied must be equal to the energy emitted in the form of photons.
The energy of a photon is given by the Planck expression
E = h f
the speed of light, wavelength and frequency are related
c = λ f
we substitute
E =
a red photon has a wavelength of lam = 700 nm = 700 10⁻⁹ m
we calculate the energy
E = 6.626 10⁻³⁴ 3 10⁸/700 10⁻⁹
E = 2.8397 10⁻¹⁹J
therefore the charge carriers have an energy 2.8 10⁻¹⁹ J,