Scientists can tell this by looking at seismic waves released by earthquakes. ( if you need me to elaborate more ask)
Answer:
Explanation:
given,
length of ladder = 10 ft
let x be the distance of the bottom and y be the distance of the top of ladder.
x² + y² = 100
differentiating with respect to time we get
..............(1)
when x = 8 and y = 6 and when \dfrac{dx}{dt} = 1.4ft/s
from equation (1)
now,
let the angle between the ladders be θ
y = xtan θ
<span>A vector which implies that an
object has been moved or has changed its position is called displacement.
Displacement is usually associated with length and direction of an imaginary
straight point. It is the shortest distance from the initial point to the final
point of final position (P). Displacement can also be described as the length
between the final and initial point on the shortest path. It means an overall change
in direction of the object or point of a
body.</span>
<span>The force of static friction F equals the coefficient of friction u times the normal force N the object exerts on the surface: F = uN. N is the centripetal force of the wall on the people; N = ma_N, where m is the mass of the people and a_N is the centripetal acceleration.
The people will not slip down if F is greater than the force of gravitation: F = uma_N > mg, or u > g/a_N.
a_N is the velocity v of the people squared divided by the radius of the room r: a_N = v^2/r.
The circumference of the room is 2 pi r = 28.3 m. So v = 28.3 * 0.8 m/sec = 22.6 m/sec.
So a_N = 114 m/sec^2.
g = 9.81 m/sec^2, so u must be at least 9.81/114 = 0.086.</span>
Answer:
<h2>
3,343.68kJ </h2>
Explanation:
Heat energy used up can be calculated using the formula:
H = mcΔt
m = mass oof the object (in kg) = 20kg
c = specific heat capacity of water = 4179.6J/kg°C
Δt change in temperature = 80-40 = 40°C
H= 20* 4179.6 * 40
H = 3,343,680Joules
H = 3,343.68kJ
