Answer:
a. 13.7 s b. 6913.5 m
Explanation:
a. How much time before being directly overhead should the box be dropped?
Since the box falls under gravity we use the equation
y = ut - 1/2gt² where y = height of plane above ocean = 919 m, u = initial vertical velocity of airplane = 0 m/s, g = acceleration due to gravity = -9.8 m/s² and t = time it takes the airplane to be directly overhead.
So,
y = ut - 1/2gt²
y = 0 × t - 1/2gt²
y = 0 - 1/2gt²
y = - 1/2gt²
t² = -2y/g
t = √(-2y/g)
So, t = √(-2 × 919 m/-9.8 m/s²)
t = √(-1838 m/-9.8 m/s²)
t = √(187.551 m²/s²)
t = 13.69 s
t ≅ 13.7 s
So, the box should be dropped 13.69 s before being directly overhead.
b. What is the horizontal distance between the plane and the victims when the box is dropped?
The horizontal distance x between plane and victims, x = speed of plane × time it takes for box to drop = 505 m/s × 13.69 s = 6913.45 m ≅ 6913.5 m
The perimeter of ΔWXY is : ( D ) 14.5 cm
<u>Calculating the </u><u>perimeter </u><u>of ΔWXY</u>
QR = WY / 2
RS = XW / 2
QS = XY / 2
Given that : QR = 2.93 cm , RS = 2.04 cm, QS = 2.28 cm
Therefore
Perimeter of ΔWXY = ∑ WY + XW + XY
= 2SR + 2QS + 2QR
= 2(2.04) + 2(2.28) + 2(2.93)
= 14.5 cm
Hence we can conclude that the perimeter of ΔWXY = 14.5 cm
learn more about perimeter calculations : brainly.com/question/24744445
Explanation:
The de broglie wavelength is given by :
Here,
h is Planck's constant
p is momentum
Momentum and De-Broglie wavelength has inverse relationship. If momentum of an electron double, its wavelength gets half.
Answer:
because energy is used to keep the things in place
Answer:
Explanation:
Given data
Length h=2.0m
Angle α=25°
To find
Speed of bob
Solution
From conservation of energy we know that:
