Answer:
The potential energy can be given as
E = mgh. m is mass, g = acceleration due to gravity = 9.8m/s, h is the heigh, given as 100.0m
E = m x 9.8 x 100 = (980m)J
E = (980m)/10^9GJ = (0.000000980m)GJ to 3 significant figures
Explanation:
Hydroelectric dams exploit storage of gravitational potential energy. A mass, m, raised a height, h against gravity, g = 9.8 m/s², is given a potential energy E = mgh. The result will be in Joules if the input is expressed in meters, kilograms, and seconds (MKS, or SI units).
Answer:
<em>time = 6.9 s</em>
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Explanation:
velocity of the plane v = 22.7 m/s
acceleration of the train a = -3.3 m/s^2
it finally comes to res, final velocity u = 0 m/s
time t = ?
using the equation
v = u + at
substituting, we have
0 = 22.7 + (-3.3)t
0 = 22.7 - 3.3t
3.3t = 22.7
t = 22.7/3.3 = <em>6.9 s</em>
Answer:
= 391.67 Hz
Explanation:
The sound of lowest frequency which is produced by a vibrating sting is called its fundamental frequency ().
The For a vibrating string, the fundamental frequency () can be determined by:
=
Where v is the speed of waves of the string, and L is the length of the string.
L = 42.0 cm = 0.42 m
v = 329 m/s
=
=
= 391.6667 Hz
The fundamental frequency of the string is 391.67 Hz.
Answer:
The ball was in air for 3.896 s
Explanation:
given,
g = 9.8 m/s², acceleration due to gravity,
If the launch angle is 45°, the horizontal range will be maximum.
The horizontal and vertical launch velocities are equal, and each is equal to
v_h = v cos θ
v_h = 27 × cos 45°
= 19.09 m/s.
The time to attain maximum height is one half of the time of flight.
v = u + at ∵ v = 0 (max. height)
19.09 - 9.8 t₁ = 0
t₁ = 1.948 s
The time of flight is twice of the maximum height time
2 t₁ = 3.896 s
The horizontal distance traveled is
D = v × t
D = 3.896×19.09
= 74.375 m
The ball was in air for 3.896 s