Answer:
both staments are examples of scientfic laws
Explanation:
idk
Density is defined as (mass) per unit (volume). So in order to calculate
the density of a glob of some substance, you pretty much have to measure
its mass and its volume.
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:
a = 2.22 [m/s^2]
Explanation:
First we have to convert from kilometers per hour to meters per second
![40 [\frac{km}{h}]*[\frac{1h}{3600s}]*[\frac{1000m}{1km}] = 11.11 [m/s]](https://tex.z-dn.net/?f=40%20%5B%5Cfrac%7Bkm%7D%7Bh%7D%5D%2A%5B%5Cfrac%7B1h%7D%7B3600s%7D%5D%2A%5B%5Cfrac%7B1000m%7D%7B1km%7D%5D%20%3D%2011.11%20%5Bm%2Fs%5D)
We have to use the following kinematics equation:

where:
Vf = final velocity = 11.11 [m/s]
Vi = initial velocity = 0
a = acceleration [m/s^2]
t = time = 5 [s]
The initial speed is taken as zero, as the car starts from zero.
11.11 = 0 + (a*5)
a = 2.22 [m/s^2]

Since initial velocity is zero hence , u = 0
=> d = 1/2 * a * t2

on solving we get
d = 86.436 metres
Note ; Here Gravitational Acceleration is take as , g = 9.8 m/s2