Answer:
a) 6.95 m/s
b) 1.42 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²

a) The vertical speed when it leaves the ground. is 6.95 m/s

Time taken to reach the maximum height is 0.71 seconds

Time taken to reach the ground from the maximum height is 0.71 seconds
b) Time it stayed in the air is 0.71+0.71 = 1.42 seconds
The area of the bar over r=4 is 0.468
Explanation:
Given parameters:
Initial velocity = 72km/hr
Final velocity = 0km/hr
Time taken = 25s
Unknown:
Acceleration = ?
Solution:
To solve this problem, convert km/hr to m/s;
1000m = 1km
3600s = 1hr
72km/hr;
1km/hr = 0.278m/s
72km/hr = 0.278 x 72 = 20.02m/s
Acceleration is the change in velocity divided by the time taken;
Acceleration =
Acceleration =
= -0.8m/s
The car is actually decelerating at a rate of 0.8m/s
Answer:
Characteristic numbers are dimensionless numbers used in fluid dynamics to describe a character of the flow. To compare a real situation with a small-scale model it is necessary to keep the important characteristic numbers the same. Names of these numbers were standardized in ISO 31, part 12.
Explanation:
The average power output:
P = V * I * t
V = 220 V, I = 15 A;
t = 2 ms * 200 = 400 ms = 0.4 s
P = 220 V * 15 A * 0.4 s
P = 1320 W ≈ 1.3 kW
Answer:
b. 1.3 kW