Tbh ! All of them have lens but I would go with B.) Smart Phone
Hope This Helps !!!
Answer:
the crown was not made of pure gold
Explanation:
Mass of gold = weight in air/ g = 7.84N/10ms-2= 0.784 Kg or 0.8Kg
From Archimedes principle:
Upthrust= weight in air- weight in a fluid
Upthrust= volume × density × g
Note density of water = 1000kgm-3
7.84-6.84= V × 1000kgm-3×10ms-2
V= 1/10000= 1×10-4 m^3
Density = mass/ volume= 0.8/1×10-4
= 8×10^3 Kgm-3
But we know the density of gold to be 19.3 ×10^3 kgm-3
Hence the crown was not made of pure gold
Answer:
D I think I might be wrong its been a while scense I did something like that
Answer:
Time = t = 6.62 s
Explanation:
Given data:
Height = h = 215 m
Initial velocity = = 0 m/s
gravitational acceleration = g = 9.8 m/s²
Time = t = ?
According to second equation of motion
As initial velocity is zero, So the first term of right hand side of above equation equal to zero.
t² =
t =
t =
t = 6.62 s
Answer:
x = 41.28 m
Explanation:
This is a projectile launching exercise, let's find the time it takes to get to the base of the cliff.
Let's start by using trigonometry to find the initial velocity
cos 25 = v₀ₓ / v₀
sin 25 = Iv_{oy} / v₀
v₀ₓ = v₀ cos 25
v_{oy} = v₀ sin 25
v₀ₓ = 22 cos 25 = 19.94 m / s
v_{oy} = 22 sin 25 = 0.0192 m / s
let's use movement on the vertical axis
y = y₀ + v_{oy} t - ½ g t²
when reaching the base of the cliff y = 0 and the initial height is y₀ = 21 m
0 = 21 + 0.0192 t - ½ 9.81 t²
4.905 t² - 0.0192 t - 21 = 0
t² - 0.003914 t - 4.2813 =0
we solve the quadratic equation
t =
t =
t₁ = 2.07 s
t₂ = -2.067 s
since time must be a positive scalar quantity, the correct result is
t = 2.07 s
now we can look up the distance traveled
x = v₀ₓ t
x = 19.94 2.07
x = 41.28 m