Answer:
h = 181.73 m
Explanation:
given,
distance between the neighbors = 42 m
speed of the rock rolling = 6.9 m/s
vertical velocity of ball = 0 m/s
height of the cliff = ?
time taken by the ball to travel 42 m
d = s x t
s is the horizontal speed of the ball equal to 6.9 m/s
t = 6.09 s
same time will be taken by the ball to travel vertical distance
Using equation of motion
h = 181.73 m
Answer:
E. greater than the angle of incidence.
Explanation:
Snell's law states that:
(1)
where
are the refractive index of the first and second medium
are the angle of incidence and refraction, respectively
For light moving from water to air, we have:
(index of refraction of water)
(index of refraction of air)
Substituting into (1) and re-arranging the equation, we get
which means that
so, the correct answer is
E. greater than the angle of incidence.
Answer:
Ek1 = 900000 [J]
Ek1 = 400000 [J]
Explanation:
In order to solve this problem we must remember that kinetic energy is defined as the product of mass by velocity squared by a medium. Therefore using the following equation we have:
where:
m = mass = 500 [kg]
v1 = 60 [m/s]
So we have:
Ek1 = 0.5*500*(60^2)
Ek1 = 900000 [J]
and:
Ek2 = 0.5*500*(40^2)
Ek2 = 400000 [J]