The weight is 45 N, because the three chains hold the sign, and each contributes 15 N.
Notice that the mass would be the weight/acceleration of gravity, m = 45/9.8 kg. But they ask the weight (force, so Newtons)
Answer:
t=0.42s
Explanation:
Here you have an inelastic collision. By the conservation of the momentum you have:

m1: mass of the bullet
m2: wooden block mass
v1: velocity of the bullet
v2: velocity of the wooden block
v: velocity of bullet and wooden block after the collision.
By noticing that after the collision, both objects reach the same height from where the wooden block was dropped, you can assume that v is equal to the negative of v2. In other words:

Where you assumed that the negative direction is upward. By replacing and doing v2 the subject of the formula you get:

Now, with this information you can use the equation for the final speed of an accelerated motion and doing t the subject of the formula. IN other words:

hence, the time is t=0.42 s
Answer:
Option C
Explanation:
Kinetic energy is the energy that the body possesses by virtue of its motion.
The formula for Kinetic energy is given by 
Using this formula let us find kinetic energy for the bodies given and find out which is the greatest
A) KE = 
B) KE =
C) KE = 
D) KE = 
Comparing these we find that 9mv^2 is the highest.
Hence option C is the answer.
I believe that the price will rise.
Hope this helps!
Answer:
Sound intensity is the amount of energy carried by sound versus loudness is a subjective measurement of the audible sound.
Sound intensity is measured in watt per square meter where loudness is measured in sones (sone is a subjective measurement and not an SI unit)