Iron and nickel are the elements most similar to cobalt
Answer:
Explanation:
refractive index of ember = sin of angle of incidence / sin of angle of refraction
= sin 35 / sin24
= .5735 / .4067
= 1.41
This is refractive index of ember with respect to water
refractive index of ember with respect to water
= wμe = μe / μw
μe = wμe x μw
= 1.33 x 1.41
= 1.87
refractive index of ember with respect to air = 1.87 .
Answer:
SKID
Explanation:
In general, airplane tracks are flat, they do not have cant, consequently the friction force is what keeps the bicycle in the circle.
Let's use Newton's second law, let's set a reference frame with the horizontal x-axis and the vertical y-axis.
Y axis y
N- W = 0
N = W
X axis (radial)
fr = m a
the acceleration in the curve is centripetal
a =
the friction force has the expression
fr = μ N
we substitute
μ mg = m v²/r
v =
we calculate
v =
v = 1,715 m / s
to compare with the cyclist's speed let's reduce to the SI system
v₀ = 18 km / h (1000 m / 1 km) (1 h / 3600 s) = 5 m / s
We can see that the speed that the cyclist is carrying is greater than the speed that the curve can take, therefore the cyclist will SKID
Answer:
A) object moves 20 N [West] or -20 N [East]
B) object moves 6 N [South] or -6 N [North]
C) object moves 90 N [West] or -90 N [East]
D) object does not move and is at rest*
*Rest means 0
Why:
A)both forces from north and south that are pushing against the object neutralize each other. Assume that north is positive and south is negative: 20 [N] + (-20) [S] = 0
On West and east, you can see that west has a greater force. Assume that west is negative and east is positive: 50 [E] + (-70) [W] = -20 [E]
Answer:
1000 kgm²/s, 400 J
1000 kgm²/s, 1000 J
600 J
Explanation:
m = Mass of astronauts = 100 kg
d = Diameter
r = Radius =
v = Velocity of astronauts = 2 m/s
Angular momentum of the system is given by
The angular momentum of the system is 1000 kgm²/s
Rotational energy is given by
The rotational energy of the system is 400 J
There no external toque present so the initial and final angular momentum will be equal to the initial angular momentum 1000 kgm²/s
Energy
The new energy will be 1000 J
Work done will be the change in the kinetic energy
The work done is 600 J