Answer:
The object is traveling 7.5 km per hour.
Explanation:
30/4 = 7.5
To check do 7.5 * 4 and you get 30
Answer:
The rotation speed, w, is 2*pi radians/60 seconds = 0.105 rad/s and r = 0.01 m
The flea needs centripetal force given by
Fc = m*w^2/r
That force must come from friction given by
Ff = mu*N = mu*m*g
So
m*w^2/r = mu*m*g
Substitute the data, cancel the m's, and solve for mu.
Answer:
+12 m/s
Explanation:
The velocity of an object moving of accelerated motion is given by:

where
v0 is the initial velocity of the object
a is the acceleration
t is the time
In this problem, the rocket starts from rest, so
. The acceleration is
, so the velocity after
will be

Explanation:
It is given that,
Initially the car is at rest and travels for t₁ seconds with a uniform acceleration a₁. The driver then applies the brakes, causing a uniform acceleration a₂, If the brakes are applied for t₂ seconds.
We need to find the speed of the car just before the beginning of the braking period.
Using the formula of acceleration. It is given by :

u = 0

So, just before the beginning of the braking period the speed of the car is
. Hence, this is the required solution.
Answer:
λ = 396.7 nm
Explanation:
For this exercise we use the diffraction ratio of a grating
d sin θ = m λ
in general the networks works in the first order m = 1
we can use trigonometry, remembering that in diffraction experiments the angles are small
tan θ = y / L
tan θ =
= sin θ
sin θ = y / L
we substitute
= m λ
with the initial data we look for the distance between the lines
d =
d = 1 656 10⁻⁹ 1.00 / 0.600
d = 1.09 10⁻⁶ m
for the unknown lamp we look for the wavelength
λ = d y / L m
λ = 1.09 10⁻⁶ 0.364 / 1.00 1
λ = 3.9676 10⁻⁷ m
λ = 3.967 10⁻⁷ m
we reduce nm
λ = 396.7 nm