Answer:
Two equal and opposite parallel forces not acting along the same line, form a couple. A couple is always needed to produce the rotation.
For example, turning a key in a lock and turning a steering wheel.
Answer:
Time period for first satellites 24.46 days and for second satellites 37.67 days
Explanation:
Given :
Distance of first satellites
m
Distance of second satellites
m
Distance of charon
m
Time period of charon
days
From the kepler's third law,
Square of the time period is proportional to the cube of the semi major axis.


For first satellites,


days
For second satellites,


days
Therefore, time period for first satellites = 24.46 days and for second satellites 37.67 days
Answer:
Explanation:
Given
Ray of light incident on plane making an angle of
with normal
Thus incident angle 
So according to the law of incidence is equal to angle of reflection

thus 
and angle between mirror and reflected ray 

Answer:
vₓ = 20 m/s, v_{y} = -15 m / s
Explanation:
This is a conservation of moment problem, since it is a vector quantity we can work each axis independently
The system is formed by the two drones, so the forces during the crash are internal and the moment is conserved
X axis
Initial moment. Before the crash
p₀ = m₁ v₀ₓ + m₂ v₀ₓ
Final moment. After the crash
p_{fx} = (m₁ + m₂) vₓ
p₀ₓ =
m₁ v₀ₓ + m₂ v₀ₓ = (m₁ + m₂) vₓ
vₓ = (m₁ + m₂) v₀ₓ / (m₁ + m₂)
vₓ = v₀ₓ = 20 m/s
Y Axis
Initial
p_{oy} = m₁ v_{oy}
Final
p_{fy} = (m₁ + m₂) v_{y}
p_{oy} = p_{fy}
the drom rises and when it falls it has the same speed because there is no friction v_{oy} = -60 m/s
m₁
= (m₁ + m₂) v_{y}
v_{y} = m₁ / (m₁ + m₂) v_{oy}
v_{y} = 1/4 60
v_{y} = -15 m / s
Vertical speed is down