Answer:
Train accaleration = 0.70 m/s^2
Explanation:
We have a pendulum (presumably simple in nature) in an accelerating train. As the train accelerates, the pendulum is going move in the opposite direction due to inertia. The force which causes this movement has the same accaleration as that of the train. This is the basis for the problem.
Start by setting up a free body diagram of all the forces in play: The gravitational force on the pendulum (mg), the force caused by the pendulum's inertial resistance to the train(F_i), and the resulting force of tension caused by the other two forces (F_r).
Next, set up your sum of forces equations/relationships. Note that the sum of vertical forces (y-direction) balance out and equal 0. While the horizontal forces add up to the total mass of the pendulum times it's accaleration; which, again, equals the train's accaleration.
After doing this, I would isolate the resulting force in the sum of vertical forces, substitute it into the horizontal force equation, and solve for the acceleration. The problem should reduce to show that the acceleration is proportional to the gravity times the tangent of the angle it makes.
I've attached my work, comment with any questions.
Side note: If you take this end result and solve for the angle, you'll see that no matter how fast the train accelerates, the pendulum will never reach a full 90°!
Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity.
Answer:
95 %
99.7 %
Explanation:
= 166 cm = Mean
= 5 cm = Standard deviation
a) 156 cm and 176 cm


From the empirical rule 95% of all values are within 2 standard deviation of the mean, so about 95% of men are between 156 cm and 176 cm.
b) 151 cm and 181 cm


The empirical rule tells us that about 99.7% of all values are within 3 standard deviations of the mean, so about 99.7% of men are between 151 cm and 181 cm.
Answer: The stratification of earth into its geologic layers was brought about by th e formation of the earth iron core.
Explanation:
Answer:
The velocity of a ball will be "-70.13 m/s".
Explanation:
The given values are:
u = 70 m
t = 0.0 s
g = a = -9.8 m/s²
s = -1 m
v = ?
As we know,
The equation of motion will be:
⇒ 
On substituting the estimated values, we get
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
In downward direction, it will be:
⇒ 