Answer:
The speed of the sled is 3.56 m/s
Explanation:
Given that,
Mass = 2.12 kg
Initial speed = 5.49 m/s
Coefficient of kinetic friction = 0.229
Distance = 3.89 m
We need to calculate the acceleration of sled
Using formula of acceleration

Where, F = frictional force
m = mass
Put the value into the formula




We need to calculate the speed of the sled
Using equation of motion

Where, v = final velocity
u = initial velocity
a = acceleration
s = distance
Put the value in the equation



Hence, The speed of the sled is 3.56 m/s.
A solenoid hope this is right
Answer: Point A is the answer for the potential energy. Point D is the answer for the kinetic energy.
Explanation:
The photoelectric effect is obtained when you shine a light on a material, resulting in the emission of electrons.
The kinetic energy of the electrons depends on the frequency of the light:
K = h(f - f₀)
where:
K = kinetic energy
h = Planck constant
f = light frequency
f₀ = threshold frequency
Rearranging the formula in the form y = m·x + b, we get:
K = hf - hf₀
where:
K = dependent variable
f = <span>indipendent variable
h = slope
hf</span>₀ = y-intercept
Every material has its own threshold frequency, therefore, what stays constant for all the materials is h = Planck constant (see picture attached).
Hence, the correct answer is
C) the slope.