Answer:
Magnitude of displacement = 2.07 km
Magnitude of average velocity = 1.17 kmph
Explanation:
Let east represent positive x axis and north represent positive y axis.
A bird watcher meanders through the woods, walking 1.93 km due east, 1.03 km due south, and 3.84 km in a direction 52.8 ° north of west.
1.93 km due wast
s ₁ = 1.93 i km
1.03 km due south
s₂ = -1.03 j km
3.84 km in a direction 52.8 ° north of west
s₃ = -3.84 cos 52.8 i + 3.84 sin 52.8 j = -2.32 i + 3.06 j km
Total displacement
s = s ₁+ s₂+ s₃ = 1.93 i - 1.03 j -2.32 i + 3.06 j = -0.39 i + 2.03 j
Magnitude of displacement, 
Time taken = 1.771 hour
Magnitude of average velocity, 
Answer:
option A
Explanation:
given,
height of the drop of stone = 9.44 m
speed of the stone = ?
As the stone is dropped the energy of the stone will be conserved.
using conservation of energy.
Potential energy = Kinetic energy
v = 13.60 m/s
Hence, the correct answer is option A
Answer:
sofa
Explanation:
because the sofa is heavy and the amount of friction is high due to the amount of opposite friction is pushing it back
Answer:
The speed decreases.
Explanation:
This can be explained using the conservation of linear momentum.
Since there is no friction, the initial moment of the train must be equal to its linear moment after it is filled with water.
the initial linear momentum is
where 
is the initial mass of the train, and 
the initial speed of the train.
And linear momentum after the water filled the train car is
where 
is mass of the train after the rain, and 
the speed of the train after the rain
<u>the equality must be fulfilled:</u>
We know that if water is added to the train, that is the mass after the water is added, is greater than which is the mass of the train without the water.
Therefore, in order for the conservation of the linear momentum to be fulfilled:
the speed after the water is added ( ) must be smaller than the initial train speed ( ) . So the speed of the car decreases.
