We can use 3rd equation of motion to find the velocity of the stone just before it strikes the ground.
Height = S = 318 meters
Acceleration = a= 9.8 m/s²
Initial velocity = u = 0
Final velocity = v = ?
According to the 3rd equation of motion:
2aS = v² - u²
2(9.8)(318)=v²
v²=6232.8
⇒
v = 78.95 m/s
So, the velocity rounded of to nearest integer will be 79 meters per second.
Thus, C option is the correct answer
Answer:
The answer is D
The second law of thermodynamics
Answer:
118.3 J
Explanation:
Givens:
m = 1.4 kg
V = 13 m/s
Formula for kinetic energy:
KE = (1/2)*(m)*(v)^2
KE = .5*(1.4 kg)*(13 m/s)^2
KE 118.3 J
J = Joules
let the length of the beam be "L"
from the diagram
AD = length of beam = L
AC = CD = AD/2 = L/2
BC = AC - AB = (L/2) - 1.10
BD = AD - AB = L - 1.10
m = mass of beam = 20 kg
m₁ = mass of child on left end = 30 kg
m₂ = mass of child on right end = 40 kg
using equilibrium of torque about B
(m₁ g) (AB) = (mg) (BC) + (m₂ g) (BD)
30 (1.10) = (20) ((L/2) - 1.10) + (40) (L - 1.10)
L = 1.98 m
Explanation:
For a charge concentrated nearly at a point, the electric field is directly proportional to the amount of charge; it is inversely proportional to the square of the distance radially away from the centre of the source charge and depends also upon the nature of the medium.
