Average speed = (distance covered) / (time to cover the distance)
Average speed = (4 meters) / (5 seconds)
Average speed = (4/5) (meters/seconds)
Average speed = 0.8 m/s
Answer:
3.75 billion years
Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 1.25 billion years
Number of half-lives (n) = 3
Time (t) =?
The time taken for the sample of potassium-40 to contains one-eighth the original amount of parent isotope can be obtained as:
n = t / t½
3 = t / 1.25
Cross multiply
t = 3 × 1.25
t = 3.75 billion years.
Therefore, it will take 3.75 billion years for the sample of potassium-40 to contains one-eighth the original amount of parent isotope
From Newton's second law:
a = F/mass
Therefore, acceleration of an object rolling a ramp would be:
a = g(sin theta) - friction coefficient (g) (sin theta)
The negative sine is due to the kinetic energy opposing the gravity
We are given that the friction coefficient is zero, the g is a constant = 9.8 m/sec and the acceleration is 2 m/sec^2
Substituting in the equation, we get:
2 = 9.8 sin(theta)
sin (theta) = 0.20408
theta = 11.7757 degrees
The short answer is that gravitational force is so small compared to other forces (such as the attractions/repulsion between charged particles) that gravity is negligible.