Answer:
Explanation:stop it cause the sun don't shine that long unless if it's summer cause the summer time is very hot it may be 100 degrees or lower
Explanation:
Newton's second law:
∑F = ma
277 N − 245 N = (25 kg) a
a = 1.28 m/s²
Basically it is the difference in velocity divided by the time it takes to make that change.
Answer:
A.) 1430 metres
B.) 80 seconds
Explanation:
Given that the train accelerates from rest at 1.1m/s^2 for 20s. The initial velocity U will be:
U = acceleration × time
U = 1.1 × 20 = 22 m/s
It then proceeds at constant speed for 1100 m
Then, time t will be
Time = distance/ velocity
Time = 1100/22
Time = 50 s
before slowing down at 2.2m/s^2 until it stops at the station.
Deceleration = velocity/time
2.2 = 22/t
t = 22/2.2
t = 10s
Using area under the graph, the distance between the two stations will be :
(1/2 × 22 × 20) + 1100 + (1/2 × 22 × 10)
220 + 1100 + 110
1430 m
The time taken between the two stations will be
20 + 50 + 10 = 80 seconds
Efficiency = 1000/2000 = 0.5 = 50%
