A sphere is a perfect 3 demention closed surface where every point is an equal distance from the center. And a hemisphere is half of a sphere with one flat side.
The world has a total of 7 layers
Answer:
a) t = 0.90 s, b) t = 0.815 s, c) t = 0.90 s, d) x = 3.6 m, e) t = 0.639 s
Explanation:
all these exercises are about kinematics
a) The body is released from rest,
y = y₀ + v₀ t - ½ g t²
in this case when reaching the ground y = 0 and its initial velocity is vo = 0
0 = y₀ + 0 - ½ g t²
t² = 2 y₀ / g
t² = 2 4 /9.81
t² = 0.815
t = √0.815
t = 0.90 s
b) It is thrown upwards at v₀ = 4 m / s
y = y₀ + v₀ t - ½ g t²
in this case the initial and final height is the same
y = y₀ = 0
0 = v₀ t -1/2 g t²
t = 2 v₀ / g
t = 2 4 /9.81
t = 0.815 s
c) the ball is at y₀ = 4 m and its initial velocity is horizontal v₀ = 4 m / s
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 i / g
t² = 2 4 / 9.81
t² = 0.815
t = 0.90 s
d) the horizontal distance traveled is
x = v₀ₓ t
x = 4 0.90
x = 3.6 m
e) We can calculate the time to fall from I = 2 m
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 y₀i / g
t² = 2 2 /9.81
t² = 0.4077
t = 0.639 s
Therefore, when making measurements, you should find readings around this value.
Explanation:
The Coulomb's law states that the magnitude of each of the electric forces between two point-at-rest charges is directly proportional to the product of the magnitude of both charges and inversely proportional to the square of the distance that separates them:
![F=\frac{kq_1q_2}{d^2}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7Bkq_1q_2%7D%7Bd%5E2%7D)
In this case we have an electron (-e) and a proton (e), so:
![F=-\frac{ke^2}{d^2}\\F=-\frac{8.99*10^9\frac{N\cdot m^2}{s^2}(1.6*10^{-19}C)^2}{(933*10^{-9}m)^2}\\F=-2.64*10^{-16}N](https://tex.z-dn.net/?f=F%3D-%5Cfrac%7Bke%5E2%7D%7Bd%5E2%7D%5C%5CF%3D-%5Cfrac%7B8.99%2A10%5E9%5Cfrac%7BN%5Ccdot%20m%5E2%7D%7Bs%5E2%7D%281.6%2A10%5E%7B-19%7DC%29%5E2%7D%7B%28933%2A10%5E%7B-9%7Dm%29%5E2%7D%5C%5CF%3D-2.64%2A10%5E%7B-16%7DN)
In this case, the electric force is negative, therefore, the force is repulsive and its magnitude is:
![F=2.64*10^{-16}N](https://tex.z-dn.net/?f=F%3D2.64%2A10%5E%7B-16%7DN)