The word to fill in the blank is "equal". Because the time taken to rotate (spin on its axis) is equal to the time of revolution (going around the earth), this means that both have the same rate of angular rotation. So for every bit that the moon goes around its orbit around earth, the moon itself rotates accordingly to present the exact same side to earth.
Answer:
Her speed is 9.8 meter per second
Explanation:
Newton's second law states that acceleration (a) is related with force (F) by:
(1)
Here the only force acting on the firefighter is the weight F=mg so (1) is:
Solving for a:

Now with the acceleration we can use the Galileo's kinematic equation:
(2)
With Vf the final velocity, Vo the initial velocity and Δx the displacement, because the firefighter stars from rest Vo=0 so (2) is:

Solving for Vf


1.Use the balance to find the mass of the object. Record the value on the "Density Data Chart."
2.Pour water into a graduated cylinder up to an easily-read value, such as 50 milliliters and record the number.
3.Drop the object into the cylinder and record the new value in millimeters.
4.The difference between the two numbers is the object's volume. Remember that 1 milliliter is equal to 1 cubic centimeter. Record the volume on the data chart.
5.Compute the density of the object by dividing the mass value by the volume value. Record the density on the data chart.
Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :

Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :

Answer:
Velocity is 1.73 m/s along 54.65° south of east.
Explanation:
Let unknown velocity be v, mass of billiard ball be m and east direction be positive x axis.
Here momentum is conserved.
Initial momentum = Final momentum
Initial momentum = m x 2i + m x (-1)i = m i
Final momentum = m x v + m x 1.41 j = mv + 1.41 m j
Comparing
mi = mv + 1.41 m j
v = i - 1.41 j
Magnitude of velocity
Direction,
Velocity is 1.73 m/s along 54.65° south of east.