Answer:
After 9 seconds the object reaches ground.
Step-by-step explanation:
We equation of motion given as h = -16t²+128t+144,
We need to find in how many seconds will the object hit the ground,
That is we need to find time when h = 0
0 = -16t²+128t+144
16t²-128t-144= 0

Negative time is not possible, hence after 9 seconds the object reaches ground.
For number 11, you should say that there is more pollution and fossil fuels being burned.
For t1:
t1 = square root of 2h1 / g = square root of 2 * 0.5 / 9.8 = 0.319 sec
For t2:
t2 = sqaure root of 2h2 / g = square root of 2 * 1.0 / 9.8 = 0.451 sec
Wherein:
t = time(s) for the vertical movement
h= height
g = gravity (using the standard 9.8 m/sec measurement)
d1 = 1*0.319 = 0.319 m
d2 = 0.5 * 0.451 = 0.225 m
Where:
d = hor. distance
ratio = d1:d2
= 0.319 : 0.225
=3.19 : 2.25
The answer is 3.19 : 2.25
Answer:
Mass and time are not vector quantities .
Explanation:
All the physical quantities can be classified into two major categories that is :
Scalar quantities
- They are those that describes only the magnitude and they are regarded as incomplete quantities as they don't provide complete information.
For example : Speed ,Mass, Time etc
Vector quantities
- They are complete quantities that can be described in magnitude as well as direction .
For example : Velocity ,gravity ,Acceleration etc