That particular strike was very roughly 2.4 km (1.5 miles) away from them.
That's if you use 340 m/s (1120 ft/sec) for the speed of sound.
But the air in the region for several thousand feet around a thunderstorm
is doing weird things to sounds that pass through it, so you can't use any
exact number for the speed of sound in a stormy area.
The only thing you can be absolutely sure of is that Johnny and his friends
need to round up their equipment and get in the house. NOW !
B. A 50g fish swimming in a fish tank.
<span>14 m/s
Assuming that all of the energy stored in the spring is transferred to dart, we have 2 equations to take into consideration.
1. How much energy is stored in the spring?
2. How fast will the dart travel with that amount of energy.
As for the energy stored, that's a simple matter of multiplication. So:
20 N * 0.05 m = 1 Nm = 1 J
For the second part, the energy of a moving object is expressed as
KE = 0.5 mv^2
where
KE = Kinetic energy
m = mass
v = velocity
Since we now know the energy (in Joules) and mass of the dart, we can substitute the known values and solve for v. So
KE = 0.5 mv^2
1 J = 0.5 0.010 kg * v^2
1 kg*m^2/s^2 = 0.005 kg * v^2
200 m^2/s^2 = v^2
14.14213562 m/s = v
So the dart will have a velocity of 14 m/s after rounding to 2 significant figures.</span>
Answer: Weight = 98.1N
Explanation:
Density of water = 1000 kg/m^3
Given that the Plastic foam is about 0.10 times as dense as water. That is,
Density of plastic foam = 0.1 × 1000 = 100kg/m^3
The volume V = 1 ×1×0.1 = 0.1 m^3
Density is the ratio of mass to volume
Density = mass/volume
Let us substitute for density and volume to get mass.
100 = M/0.1
Make M the subject of formula
M = 100 × 0.1 = 10 kg
Weight = mg
Where g = 9.81 m/s
Substitute the M and g into the formula
Weight = 10 × 9.81 = 98.1 N
Therefore, the weight of the brick is 98.1 N
Answer:
The atomic model, the structure of the solar system, and the theory of black holes are examples of models created using indirect evidence.
Explanation:
I have no explanation sorry.