Answer:
There are basically seven spectral types which are used for classifying the stars and it is arranged in the order of increasing temperature from the hottest temperature to the coldest division are: O, B, A, F, G, K, and M. These categories are basically divided into the sub category in the spectral where O is the hottest type and M is the coldest type.
We have the equation of motion
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here s = 300 m, u = 0 m/s, a = 9.81
Substituting

Now we have v = u+at, where v is the final velocity
Here u = 0 m/s, a= 9.81
and t = 7.82 seconds
Substituting
v = 0+9.8*7.82 = 76.68 m/s
The speed with which the penny strikes the ground = 76.68 m/s.
The answer is static friction. This is the friction that involves objects that do not move.
Answer:
86.4 m horizontal from landing spot
Explanation:
Find out how long before the ball hits the ground
vertical speed of ball = -2 m/s gravity = - 9.81 m/s^2
find time to hit ground from 100 m
( height will be<u> zero</u> when it hits the ground)
<u>0 </u>= 100 - 2 t - 1/2 ( 9.81) t^2
use Quadratic Formula to find t = 4.32 seconds
horizontal speed of ball = 20 m/s
in 4.32 seconds it will travel horizontally 20 m/s * 4.32 s = 86.4 m
Acceleration = (change in speed) / (time for the change)
change in speed = (speed at the end) minus (speed at the beginning)
change in speed = (zero) minus (28 m/s) = -28 m/s
Acceleration = (-28 m/s) / (13 sec)
Acceleration = -2.15 m/s²