Answer:
t = 2.2 s
Explanation:
Given that,
A person observes a firework display for A safe distance of 0.750 km.
d = 750 m
The speed of sound in air, v = 340 m/s
We need to find the between the person see and hear a firework explosion. let it is t. So, using the formula of speed.

So, the required time is 2.2 seconds.
I think I can answer your question since I've worked on this before.
Your answer should be obtain energy.
If your answer choices were;
obtain energy
escape predators
produce offspring
excrete waste
Answer:
positive
Explanation:
The ball is rolling down with a negative velocity, but the velocity is slowing down. therefore the velocity must increase in order for the ball to slow down.
For example let the ball's initial velocity be -15 m/s. and it is slowing down to let's say -13 m/s. Well this means that it's velocity has increase by 2 m/s. So, its acceleration is positive.
Answer:
0.363999909622
Explanation:
F = Force
m = Mass = 15.6 g
C = Drag coefficient
ρ = Density of air = 1.21 kg/m³
A = Surface area = 
v = Terminal velocity = 
s = Displacement = 150 m

Force is given by
F = ma

The drag coefficient is 0.363999909622 (ignoring negative sign)
Answer:
According to newton's second law of motionF=ma Data:-F=3200kgm/sec² or N ,a=2m/sec² ,m=? solution :-F=ma here we have to find m so m=F/a ,m=3200/2=1600kg