Answer:
Explanation:
Small grains are negatively charged by the wind while big grains is positively charged and remains at the ground . This process creates an electric field due to the presence of oppositely charged particles.
When ever electric field exists it is directed from a positive charge to a negative charge so the here electric field is towards an upwards direction.
Answer:
9.21954 m/s
54 m/s²
Angle is zero
Explanation:
r = Radius of arm = 1.5 m
= Angular velocity = 6 rad/s
The horizontal component of speed is given by
The vertical component of speed is given by
The resultant of the two components will give us the velocity of hammer with respect to the ground
The velocity of hammer relative to the ground is 9.21954 m/s
Acceleration in the vertical component is zero
Net acceleration is given by
Net acceleration is 54 m/s²
As the acceleration is towards the center the angle is zero.
Answer:
Power = 180 Watt.
Explanation:
W = Work done = m x g x H.
m = mass of the body.
g = acceleration due to gravity = 9.8 m/s^2.
W = weight of the body = m x g = 720 N.
H = height of the body = 5 m.
t = Time = 20 s.
Plugging the above values in the formula we get:
W = 720 x 5 = 3600 J.
Power = 
= 
= 180 Watt.
Therefore the required value of power = 180 Watt.
Answer:
The variation is inversely proportional to the decrease density
Explanation:
This is an exercise where we will use the Archimedes principle that states that the thrust is equal to the weight of the dislodged liquid
B = m g
ρf = m / Vf
m = ρf Vf
B = ρf Vf g
If we use Newton's second law for equilibrium
B - W = 0
B = m g
ρ Vf g = ρb Vb g
ρb / ρf = Vf / Vb (1)
Let's apply this expression to our case
In water
Vf / Vg = 0.90
replace in equation 1
ρb / ρf = 0.90
ρb = ρf 0.90
ρb = 1000 0.90
ρb = 900 kg / m3
Now we change the liquid to one with lower density, let's calculate the volume ratio
Vf / Vg = ρb / ρf
The density of the body (ρb) remains constant if the density of the fluid decreases, as in the denominator the volume fraction increases, whereby the submerged part decreases
The variation is inversely proportional to the decrease density
The answer to the first question is that, the sumo wrestler loses energy equal to the absorbed energy of the trampoline plus the air friction drag loss. With the second question, the gymnast should maintain energy equal to the Potential energy gymnast has at the peak of bounce height by exerting little force to compensate for the energy spent on the internal friction of the trampolines action.
