Answer:
4.4 seconds
Explanation:
Given:
a = -5.5 m/s²
v₀ = 0 m/s
y₀ = 53 m
y = 0 m
Find: t
y = y₀ + v₀ t + ½ at²
0 = 53 + 0 + ½ (-5.5) t²
0 = 53 − 2.75 t²
t = 4.39
Rounded to two significant figures, it takes 4.4 seconds for the object to land.
Answer:

Explanation:
<u>Accelerated Motion
</u>
When a body changes its speed at a constant rate, i.e. same changes take same times, then it has a constant acceleration. The acceleration can be positive or negative. In the first case, the speed increases, and in the second time, the speed lowers until it eventually stops. The equation for the speed vf at any time t is given by

where a is the acceleration, and vo is the initial speed
.
The train has two different types of motion. It first starts from rest and has a constant acceleration of
for 182 seconds. Then it brakes with a constant acceleration of
until it comes to a stop. We need to find the total distance traveled.
The equation for the distance is

Our data is

Let's compute the first distance X1


Now, we find the speed at the end of the first period of time


That is the speed the train is at the moment it starts to brake. We need to compute the time needed to stop the train, that is, to make vf=0



Computing the second distance


The total distance is



Light can't reflect off them I think
Answer:
The average acceleration is 16.6 m/s² ⇒ 1st answer
Explanation:
A rocket achieves a lift-off velocity of 500.0 m/s from rest in
30.0 seconds
The given is:
→ The initial velocity = 0
→ The final velocity = 500 meters per seconds
→ The time is 30 seconds
Acceleration is the rate of change of velocity of the rocket
→ 
where a is the acceleration, v is the final velocity, u is the initial velocity
and t is the time
→ u = 0 , v = 500 m/s , t = 30 s
Substitute these values in the rule
→
m/s²
<em>The average acceleration is 16.6 m/s²</em>