Answer:
H = 3.9 m
Explanation:
mass (m) = 48 kg
initial velocity (initial speed) (U) = 8.9 m/s
final velocity (V) = 1.6 m/s
acceleration due to gravity (g) = 9.8 m/s^{2}
find the height she raised her self to as she crosses the bar (H)
from energy conservation, the change in kinetic energy = change in potential energy
0.5m(V^{2} - [test]U^{2}[/tex]) = mg(H-h)
where h = initial height = 0 since she was on the ground
the equation becomes
0.5m(V^{2} - [test]U^{2}[/tex]) = mgH
0.5 x 48 x (1.6^{2} - [test]8.9^{2}[/tex]) = 48 x 9.8 x H
-1839.6 = 470.4 H (the negative sign indicates a decrease in kinetic energy so we would not be making use of it further)
H = 3.9 m
Answer: 3.75 joules
Explanation:
Given that:
Mass of acorn = 0.300 kilograms
velocity = 5.oo m/s
Kinetic energy = ?
Since, kinetic energy is the energy possessed by a moving object, its value depends on the mass M and velocity V of the acorn.
Thus, Kinetic energy = 1/2 x mv^2
= 1/2 x 0.300kg x (5.00m/s)^2
= 0.5 x 0.3kg x (5.00m/s)^2
= 0.15 x (5.00m/s)^2
= 3.75 joules
Thus, the kinetic energy of the falling acorn is 3.75 joules
Answer:
<em>155.80rad/s</em>
Explanation:
Using the equation of motion to find the angular acceleration:
is the final angular velocity in rad/s
is the initial angular velocity in rad/s
is the angular acceleration
t is the time taken
Given the following
Time = 4.1secs
Convert the angular velocity to rad/s
1rpm = 0.10472rad/s
6100rpm = x
x = 6100 * 0.10472
x = 638.792rad/s
Get the angular acceleration:
Recall that:
638.792 = 0 + ∝(4.1)
4.1∝ = 638.792
∝ = 638.792/4.1
∝ = 155.80rad/s
<em>Hence the angular acceleration as the blades slow down is 155.80rad/s</em>
The amount of diffraction of sound waves depends on the medium the sound wave travels to and the frequency. Diffraction happens as soon as it has been out of the source.
