Average speed = (total distance covered) / (time to cover the distance)
-- Traveling at 40 mph for 1 hour, the distance covered is 40 miles.
-- Traveling at 60 mph for 1 hour, the distance covered is 60 miles.
-- Total distance covered = (40 miles) + (60 miles) = 100 miles
-- Total time = (1 hour) + (1 hour) = 2 hours
-- Average speed = (100 miles) / (2 hours)
<em>Average speed = 50 miles per hour</em>
Answer:
Vf = 210 [m/s]
Av = 105 [m/s]
y = 2205 [m]
Explanation:
To solve this problem we must use the following formula of kinematics.
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (released from the rest)
g = gravity acceleration = 10 [m/s²]
t = time = 21 [s]
Vf = 0 + (10*21)
Vf = 210 [m/s]
Note: The positive sign for the gravity acceleration means that the object is falling in the same direction of the gravity acceleration (downwards)
The average speed is defined as the sum of the final speed plus the initial speed divided by two. (the initial velocity is zero)
Av = (210 + 0)/2
Av = 105 [m/s]
To calculate the distance we must use the following equation of kinematics
44100 = 20*y
y = 2205 [m]
In scientific notation, if the exponent of 10 is positive, the number is very very large. In the metric system, very large numbers are expressed in megameters (Mm) or gigameters (Gm). Gigameters is equal to 10⁹ meters. So, in SI prefix, that would be equal to 150 Gm. In kilometers, that would be equal to:
1.5×10¹¹ m * (1 km/1000 m) = 1.5×10⁸ km
As science being dynamic many things will change and due to this changes many things and theories will be new to us. the model of the atom is not weak, it is just developing as time progress because in the early times it is not fully understood because of the lack of technology to study, what scientist do is just filling the knowledge gap of the previous studies.
