An extraterrestrial "Eratosthenes" performs the equivalent experiment, that Eratosthenes did on Earth, on her/his home world. Sh
1 answer:
Answer:
a. 2865 km
Explanation:
Eratosthenes observed that the sun's rays formed a vertical angle of 7º 12 ’. Which confirmed that the Earth was not flat, assuming that it had a spherical shape, using the distance between Alexandria and Siena and the measure of the angle of inclination of the solar rays in Alexandria, calculated the circumference of the Earth.
The calculation was made with a simple rule of three:
angle of inclination of the solar rays——————- distance
360º ————- Planet circumference
And since we know that:
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Answer:
- The maximum height reached by the ball is 45.92 m
- Time taken to fall down to half of its height is 2.2 s
Explanation:
Given;
initial velocity of the ball, u = 30 m/s
final velocity of the ball at the highest point, v = 0
The maximum height reached by the ball is calculated as;
v² = u² - 2gh
where;
h is the maximum height reached by the ball
0 = 30² - (2 x 9.8)h
19.6h = 900
h = 900 / 19.6
h = 45.92 m
Time taken to fall to half of its height is calculated as;
when falling down, the final velocity v becomes the initial velocity = 0.
Apply the following kinematic equation;
h = ut + ¹/₂gt²
h = 0 + ¹/₂gt²
h = ¹/₂gt²
where;
h = 45.92 m is the maximum height reached
half of h = 45.92 / 2 = 22.96 m
22.96 = ¹/₂gt²
Answer:
The magnitude of the electric force on a protein with this charge is
Explanation:
Given that,
Electric field = 1500 N/C
Charge = 30 e
We need to calculate the magnitude of the electric force on a protein with this charge
Using formula of electrostatic force
Where, F = force
E = electric field
q = charge
Put the value into the formula
Hence, The magnitude of the electric force on a protein with this charge is