Answer:
18.1 MN/C
Explanation:
The gravitational force of the plastic sphere is in equilibrium with the electric force.
Mass of the plastic sphere = m = 14.2 g = 0.0142 kg
Force of gravity = F = mg = (0.0142)(9.81) = 0.139 N
This force is balanced by the electric force due to the charge 7.7 nC
Charge = q = 7.7 x 10⁻⁹ C
Electric field = E = F / q = (0.139) /(7.7 x 10⁻⁹) = 18.1 MN/C
Answer:
the sound intensity level for actual intensity ( without the earplugs ) is 103.8 dB
Explanation:
Given the data in the question;
sound intensity reduced by the factor, m = 305
the sound intensity level experienced by the crew members wearing protective earplugs, L = 79 dB
Now, using the expression of sound intensity level;
L = 10log( )
where is the intensity at L level
so we substitute
79 = 10log( )
=
Now, expression for actual intensity;
= m
where is the actual intensity
so we substitute
= 305 ×
Next, we write the expression of sound intensity level for reduced intensity;
L' = 10log( )
So we substitute
L' = 10log( 305 × )
L' = 10log( 24227011159.09058 )
L' = 103.8 dB
Therefore, the sound intensity level for actual intensity ( without the earplugs ) is 103.8 dB
Answer:
Explanation:
Hi!
We define the point (0,0) as the intial position of the ball. The initial velocity is
The motion of the ball in the horizontal direction (x) has constant velocity, because there is no force in that direction. :
In the vertical direction (y), there is the downward acceleration g of gravity:
(note the minus sign of acceleration, because it points in the negative y-direction)
When the ball hits the ground, at t = 65s, y(t = 65 s) = 0. We use this to find the value of the initial vertical velocity:
We used that g = 9.8 m/s²
To find the horizonttal component we use the angle:
The answer is negative 14