Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:
Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:
When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:
Since the energy is conserved, U1=U2
For the speed to be double, we need to drop the snowball from a height H', and:
Operating:
Dividing [2] by [1]
Simplifying:
Thus:
H' = 4H
Correct choice: b 4H
Answer:
option C
Explanation:
given,
Q = +3.2 x 10⁻¹⁹ C
E = 5.0 X 10⁵ V/m
B = 0.80 T
ion's acceleration is zero
when acceleration is zero the magnitude of both the forces becomes equal.
q E = q V B
v =
v=
v = 6.25 × 10⁵ m/s ≈ 6.3 × 10⁵ m/s
hence, the correct answer is option C
Answer: Lemon blossoms falling off a potted lemon tree may also be caused by cool drafts, as well as under or over watering. A lemon tree dropping flowers may be a sign of drought or other changes in watering. When water is scarce, a lemon tree will drop flowers or fruit to conserve energy. Flooding, waterlogged soil or over-watering can also cause ...
Explanation:
Answer:
The natural frequency = 50 rad/s = 7.96 Hz
Damping ratio = 0.5
Explanation:
The natural frequency is calculated in this manner
w = √(k/m)
k = spring constant = 5 N/m
m = mass = 2 g = 0.002 kg
w = √(5/0.002) = 50 rad/s
w = 2πf
50 = 2πf
f = 50/(2π) = 7.96 Hz
Damping ratio = c/[2√(mk)] = 0.1/(2 × √(5 × 0.002)) = 0.5