Answer:
The car stops in 7.78s and does not spare the child.
Explanation:
In order to know if the car stops before the distance to the child, you take into account the following equation:
(1)
vo: initial speed of the car = 45km/h
a: deceleration of the car = 2 m/s^2
t: time
xo: initial distance to the child = 25m
x: final distance to the child = 0m
It is necessary that the solution of the equation (1) for time t are real.
You first convert the initial speed to m/s, then replace the values of the parameters and solve the quadratic polynomial for t:


You take the first value t1 because it has physical meaning.
The solution for t is real, then, the car stops in 7.78s and does not spare the child.
Answer:
3000 hurs
Explanation: just divide 150000 by 50 and get 3000
Answer: 49.5 m
Explanation:
The speed of sound
is given by a relation between the distance
and the time
:
(1)
Where:
is the speed of sound in air (taking into account this value may vary according to the medium the sound wave travels)
since we are told th hunter was initially 412.5 meters from the cliff and then moves a distance
towards the cliff
Since the time given as data (2.2 s) is the time it takes to the sound wave to travel from the hunter's gun and then go back to the position where the hunter is after being reflected by the cliff
Having this information clarified, let's isolate
and then find
:
(2)
(3)
Finding
:
This is the distance at which the hunter is from the cliff.
The meaning of inference is the process of inferring something and it is a noun
Answer:
<u>We are given:</u>
u = 2.5 m/s
a = 0.2 m/s/s
t = 25 seconds
v = v m/s
<u>Solving for 'v':</u>
From the first equation of motion:
v = u + at
Replacing the values
v = 2.5 + (0.2)(25)
v = 2.5 + 5
v = 7.5 m/s