I think, I do think.. that it is D.
Wouldn't it be simple to divide 5 from 20, that would equal 4.
4 earthworms per square meter.
Answer:
Explanation:
Applied force, F = 18 N
Coefficient of static friction, μs = 0.4
Coefficient of kinetic friction, μs = 0.3
θ = 27°
Let N be the normal reaction of the wall acting on the block and m be the mass of block.
Resolve the components of force F.
As the block is in the horizontal equilibrium, so
F Cos 27° = N
N = 18 Cos 27° = 16.04 N
As the block does not slide so it means that the syatic friction force acting on the block balances the downwards forces acting on the block .
The force of static friction is μs x N = 0.4 x 16.04 = 6.42 N .... (1)
The vertically downward force acting on the block is mg - F Sin 27°
= mg - 18 Sin 27° = mg - 8.172 ... (2)
Now by equating the forces from equation (1) and (2), we get
mg - 8.172 = 6.42
mg = 14.592
m x 9.8 = 14.592
m = 1.49 kg
Thus, the mass of block is 1.5 kg.
Thermometer-temperature
Wind vane -wind direction
Anemometer- both wind speed (and direction)
Hygrometer- humidity
Answer:
A. The upward pressure gradient force is balanced by gravity.
Explanation:
A. is correct because the pressure difference is actually generated by gravity. As in the following formula for the pressure at different points:

where
are the pressure at 2 points, ρ is the density of the fluid, g is the gravitational constant, and h is the height difference.
B is incorrect because friction in air is too small to make an effect.
C is incorrect because the Coriolis force is horizontal, not vertical.
D is incorrect because a difference of 500 hPa = 50000 Pa, this is half of the atmospheric pressure.
E is incorrect because temperature cannot generate force.
Since g is constant, the force the escaping gas exerts on the rocket will be 10.4 N
<h3>
What is Escape Velocity ?</h3>
This is the minimum velocity required for an object to just escape the gravitational influence of an astronomical body.
Given that the velocity of a 0.25kg model rocket changes from 15m/s [up] to 40m/s [up] in 0.60s. The gravitational field intensity is 9.8N/kg.
To calculate the force the escaping gas exerts of the rocket, let first highlight all the given parameters
- Mass (m) of the rocket 0.25 Kg
- Initial velocity u = 15 m/s
- Final Velocity v = 40 m/s
- Gravitational field intensity g = 9.8N/kg
The force the gas exerts of the rocket = The force on the rocket
The rate change in momentum of the rocket = force applied
F = ma
F = m(v - u)/t
F = 0.25 x (40 - 15)/0.6
F = 0.25 x 41.667
F = 10.42 N
Since g is constant, the force the escaping gas exerts on the rocket is therefore 10.4 N approximately.
Learn more about Escape Velocity here: brainly.com/question/13726115
#SPJ1