Answer:
Explanation:
101 dB = 10.1 B.
Maximum intensity of sound allowed = 10.1 B
Intensity of sound in terms of W/m² can be found as follows
log (I / I₀) = 10.1
I / I₀ = 10¹⁰°¹
I = I₀ X 10¹⁰°¹
= 10⁻¹² X 10¹⁰°¹
= 10⁻¹°⁹ W/m²
105 m above the ground the this intensity will be 105² times
intensity at source point = 10⁻¹°⁹ x 105²
= 138.79 W/m²
energy of sound from source
= 4π times
= 4 x 3.14 x 138.79
= 1743.28W/m²
To calculate in terms of decibel :
log 1743.28 / 10⁻¹²
= log 1743.28 +12
= 15.24 B
= 152.4 dB .
152.4 dB .
<span>a. address all components of fitness
</span>According to the exercise principle of balance, a workout should address all components of fitness.
<span>NOT:
</span>b. focus on balance and coordination
<span>c. target specific areas for improvement </span>
<span>d. vary exercise activities over time</span>
The shot putter should get out of the way before the ball returns to the launch position.
Assume that the launch height is the reference height of zero.
u = 11.0 m/s, upward launch velocity.
g = 9.8 m/s², acceleration due to gravity.
The time when the ball is at the reference position (of zero) is given by
ut - (1/2)gt² = 0
11t - 0.5*9.8t² = 0
t(11 - 4.9t) = 0
t = 0 or t = 4.9/11 = 0.45 s
t = 0 corresponds to when the ball is launched.
t = 0.45 corresponds to when the ball returns to the launch position.
Answer: 0.45 s
Answer:
(a) 
(b) 
(c) K.E. = 21.168 J
(d) 
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,
- constant downward acceleration,
That a constant upward acceleration of 
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,
∴Work by the cord on the block,
We take -ve sign because the direction of force and the displacement are opposite to each other.
(b)
Force on the block due to gravity:
∵the gravity is naturally a constant and we cannot change it
∴Work by the gravity on the block,
(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:
K.E. = 21.168 J
(d)
From the equation of motion:
putting the respective values:
is the speed when the block has fallen 4.2 meters.
Um ok so you subtract 2 on both side the plug in 6
