Answer:
Explanation:
27dB = 2.7 B
So I / I₀ = 10⁻²°⁷ , I₀ is intensity of main sound and I is intensity after reduction.
= 1.99 X 10⁻³
So intensity will reduce by 1.99 X 10⁻³ .
Answer:
Peer Review
Explanation:
When scientist check other scientists the process is dubbed "peer review".
Acceleration=force/mass=28/(10+4)=2m/s^2
force10kg=ma=10*2
force4kg=ma=(10*2)=20
the4 kg is pushing against the 10kg block
vf=vi+at
-10=20*28/14 * t
t=30/2=15sec
i hope this can help you.
Answer:
the kinetic energy lost due to friction is 22.5 J
Explanation:
Given;
mass of the block, m = 0.2 kg
initial velocity of the block, u = 25 m/s
final velocity of the block, v = 20 m/s
The kinetic energy lost due to friction is calculated as;

Therefore, the kinetic energy lost due to friction is 22.5 J
Answer:
Groceries stay in the bag.
Explanation:
Given:
Maximum force = 250 N
Bag filled with = 20 kg
Lifted acceleration = 
Solution:
We need to calculate the exerted force on the grocery bag by using Newton's second law.

Where:
F = Exerted force on the object.
m = Mass of the object in kg
a = Acceleration of the object in 
Now, we substitute m = 20 kg and a =
in Newton's second law,


Since, the exerted force on the bag is less than 250 N, the groceries will stay in the bag.