Answer:
T = 2.4 + 2.4 = 4.8 [s]
Explanation:
In order to solve this problem, we must use the following kinematics equation and calculate the acceleration value.

Vo = inital velocity = 0
x - xo = 15 [m]
t = time = 2.4 [s]
15 = 0.5*a*(2.4)^2
a = 5.208 [m/s^2]
We can use the same equation to find the time.
30 = 15 + 0.5*(5.208)*t^2
t = 2.4 [s]
T = 2.4 + 2.4 = 4.8 [s]
Answer:
B. 17.15 watts
Explanation:
Given that
Time = 10 seconds
height = distance = 0.7 meters
weight of sack = mg = F = 245 newtons
Power = work done/ time taken
Where work done = force × distance
Substituting the given parameters into the formula
Work done = 245 newton × 0.7 meters
Work done = 171.5 J
Recall,
Power = work done/time
Power = 171.5 J ÷ 10
Power = 17.15 watts
Hence the power expended is B. 17.15 watts
The velocity at the maximum height will always be 0. Therefore, you will count your final velocity as 0, and your initial velocity as 35 m/s. Next, we know that the acceleration will be 9.8 m/s^2. How? Because the ball is thrown directly upward, and the only force acting on it will be the force of gravity pushing it back down.
The formula we use is h = (Vf^2 - Vi^2) / (2*-9.8m/s^2)
Plugging everything in, we have h = (0-1225)/(19.6) = 62.5 meters is the maximum height.
Answer: for insulation of heat
Explanation:
Windows in cold countries have double glazing windows to provide a barrier against the outside temperature by creating a buffer zone between two glasses.
The air or any other gas-filled between the glasses act as an insulator and offer great resistance to outside temperature thereby maintaining the inside temperature intact.