Answer:
Time, t = 13.34 seconds.
Explanation:
Given the following data;
Initial velocity, u = 85km/hr to meters per seconds = 85*1000/3600 = 23.61 m/s
Final velocity, v = 45km/hr to meters per seconds = 45*1000/3600 = 12.5 m/s
Acceleration, a = -3 km/hr/sec to meters per seconds square = -3*1000/3600 = -0.833m/s²
To find the time;
Acceleration = (v - u)/t
-0.833 = (12.5 - 23.61)/t
-0.833t = -11.11
t = 11.11/0.833
Time, t = 13.34 seconds.
Answer:
The correct option is;
C. 1,715 m
Explanation:
We are given the information from the group of teen at the City edge
Time of arrival of explosion sound = 5 s after sighting
Time of sighting explosion = 5 s before hearing the boom
Speed of sound in air ≈ 343 m/s
Speed of light = 299,792 km/s
Therefore, distance covered by sound in 5 seconds is given by the following equation;


Hence Distance = 343 m/s × 5 s = 1715 m
To check, we compare the time it would take for the light to cover 1715 m
That is
which is instantaneous hence the distance can be approximated by the time duration for the speed of sound.
Therefore, the distance of the students from the factory is approximately 1,715 m
Answer:
I don't know sorry For this question
Answer:
t = 3 seconds
Explanation:
Given that,
Initial speed, u = 30 m/s
Final speed, v = 0
It slides 45 m to rest.it take the box to come to rest
We need to find how long it take the box to come to rest.
Let a be the acceleration and t is time.

Now finding time.

So, the required time is 3 seconds.