To answer this problem, we will use the equations of motions.
Part (a):
For the ball to start falling back to the ground, it has to reach its highest position where its final velocity will be zero.
The equation that we will use here is:
v = u + at where
v is the final velocity = 0 m/sec
u is the initial velocity = 160 m/sec
a is acceleration due to gravity = -9.8 m/sec^2 (the negative sign is because the ball is moving upwards, thus, its moving against gravity)
t is the time that we want to find.
Substitute in the equation to get the time as follows:
v = u + at
0 = 160 - 9.8t
9.8t = 160
t = 160/9.8 = 16.3265 sec
Therefore, the ball would take 16.3265 seconds before it starts falling back to the ground
Part (b):
First, we will get the total distance traveled by the ball as follows:
s = 0.5 (u+v)*t
s = 0.5(160+0)*16.3265
s = 1306.12 meters
The equation that we will use to solve this part is:
v^2 = u^2 + 2as where
v is the final velocity we want to calculate
u is the initial velocity of falling = 0 m/sec (ball starting falling when it reached the highest position, So, the final velocity in part a became the initial velocity here)
a is acceleration due to gravity = 9.8 m/sec^2 (positive as ball is moving downwards)
s is the distance covered = 1306.12 meters
Substitute in the above equation to get the final velocity as follows:
v^2 = u^2 + 2as
v^2 = (0)^2 + 2(9.8)(1306.12)
v^2 = 25599.952 m^2/sec^2
v = 159.99985 m/sec
Therefore, the velocity of the ball would be 159.99985 m/sec when it hits the ground.
To find the accurate measurement of small cars, the teacher asks students to make all the measurements in centimeters.
Centimeters Measurements:
- A centimeter is a metric unit of measurement used for measuring the length of an object, It is written as cm
- Centimeter is one hundredth of a meter, 1 meter is 0.01 cm.
Inches measurements:
- An inch can be defined as a unit of length in the customary system of measurement. Length in inches is either represented by in or ''.
- 1 meter is equal to 39.37 inches
here, the cars are small objects.
The number of centimeters is always bigger,
because a centimeter unit is smaller than an inch unit, and it takes more of them when we are measuring.
Hence,
To find the accurate measurement of small cars, the teacher asks students to make all the measurements in centimeters.
Learn more about accurate measurement here:
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The correct answers are: Options 2,4 and, 5
2)He solved Ptolemy’s model by proving elliptical orbits.
4)He determined that planets move faster when closer to the Sun.
5)He discovered laws of planetary motion.
Answer:
There is no displacement.
Explanation:
Because the runner is running laps and returning to the original place, there is no displacement as displacement is relative to the change in location from the original position.
Hope this helps. . .
ly UwU