Answer:
12m/s
Explanation:
x = (21 + 22t – 6 t2) m,
We can express change bin velocity as
dx/dt= -12t + 22
But Velocity is changing
interval t = 1 s
t = 4 s
at t = 1, x = 21 + 22(1) -6(1)^2
=37
at t = 4, x = 21 + 22(4) -6(4)^2
=13
Distance travelled at interval t = 1 s
t = 4 s
X2 - X1=13- 37. = - 24m
Velocity= displacement/ time
= 24/(3-1)=12 m/s
Index fossils are used to determine the relative ages of rock and fossils and are also used to define the boundaries between geologic periods.
<u>Option: A</u>
<u>Explanation:</u>
The fossils which are recognized as fossils guides or indicator fossils are used to classify and recognize geological or faunal periods, termed as index fossils. It must be of short vertical reach, wide geographic distribution and swift patterns in evolution. It helps to assess the rock layers ' age and helps to date other fossils found close and around them. For an instance, Ammonites were abundant in the Mesozoic period between 245 to 65 mya, they have not been found after the Cretaceous era, as they became endangered during the K-T extinction (65 mya).
Answer:
they differ each other bc it is a lot of with earth quakes and everything.
Explanation:
Answer:
W = 9.93 10² N
Explanation:
To solve this exercise we must use the concept of density
ρ = m / V
the tabulated density of copper is rho = 8966 kg / m³
let's find the volume of the cylindrical tube
V = A L
V = π (R_ext ² - R_int ²) L
let's calculate
V = π (4² - 2²) 10⁻⁴ 3
V = 1.13 10⁻² m³
m = ρ V
m = 8966 1.13 10⁻²
m = 1.01 10² kg
the weight of the tube
W = mg
W = 1.01 10² 9.8
W = 9.93 10² N
