Answer:
(for small oscillations)
Explanation:
The total energy of the pendulum is equal to:

For small oscillations, the equation can be re-arranged into the following form:

Where:
, measured in radians.
If the amplitude of pendulum oscillations is increase by a factor of 4, the angle of oscillation is
and the total energy of the pendulum is:

The factor of change is:


Answer:
(A) The speed just as it left the ground is 30.25 m/s
(B) The maximum height of the rock is 46.69 m
Explanation:
Given;
weight of rock, w = mg = 20 N
speed of the rock at 14.8 m, u = 25 m/s
(a) Apply work energy theorem to find its speed just as it left the ground
work = Δ kinetic energy
F x d = ¹/₂mv² - ¹/₂mu²
mg x d = ¹/₂m(v² - u²)
g x d = ¹/₂(v² - u²)
gd = ¹/₂(v² - u²)
2gd = v² - u²
v² = 2gd + u²
v² = 2(9.8)(14.8) + (25)²
v² = 915.05
v = √915.05
v = 30.25 m/s
B) Use the work-energy theorem to find its maximum height
the initial velocity of the rock = 30.25 m/s
at maximum height, the final velocity = 0
- mg x H = ¹/₂mv² - ¹/₂mu²
- mg x H = ¹/₂m(0) - ¹/₂mu²
- mg x H = - ¹/₂mu²
2g x H = u²
H = u² / 2g
H = (30.25)² / 2(9.8)
H = 46.69 m
Answer:
C) True. At maximum displacement, its instantaneous velocity is zero.
Explanation:
The simple harmonic movement is given by
x = A cos wt
Speed
v = - A w sin wt
At the point of maximum displacement x = A
A = A cos wt
cos wt = 1
wt = 0
We replace the speed
v = -Aw sin 0 = A w
Speed is maximum
Let's review the claims
A) False. Speed is zero
B) False. It can be determined
C) True. Agree with our result
D) False. When one is maximum the other is minimum
Answer:
Here are some examples of tropism in plants : Sunflowers are one of the best examples of positive phototropism , as they always grow facing the sun.
Explanation:
Although some experts consider that perhaps such a clear growth movement should not be considered tropism.
Answer:
a=0.212 m/s²
Explanation:
Given that
q= 10⁻⁹ C
m = 5 x 10⁻⁹ kg
Magnetic filed ,B= 0.003 T
Speed ,V= 500 m/s
θ= 45°
Lets take acceleration of the mass is a m/s²
The force on the charge due to magnetic filed B
F= q V B sinθ
Also F= m a ( from Newton's law)
By balancing these above two forces
m a= q V B sinθ



a=0.212 m/s²