<u>Solution and Explanation:</u>
The following calculation is made in order to find out the area and the final velocity vector.
Using the given information and the data in the question,
m1u1 + m2u2 = (m1 + m2) multiply with v
40000 multiply with ( -20i ) + 60000 multiply with ( 10j ) = 100000 multiply with v
Therefore, v = -8i + 6j
That is |v| = 10 knots towards the 36.86 degree north of the west
Answer:
<em>The skydiver needs 0.71 seconds to reach 7 m/s</em>
Explanation:
<u>Free Fall Motion
</u>
When an object is dropped in free air (no friction) from a certain height h, it follows a free-fall motion, whose acceleration is due exclusively to gravity. The speed at a moment t when the object is dropped (from rest) is:

We need to find How long does the skydiver needs to reach 7 m/s. We solve for t



The skydiver needs 0.71 seconds to reach 7 m/s
Answer:
77.96dB
Explanation:
Recall that decibels are a unit of measuring intensity of sound, and depend on the logarithm of the intensity
the intensity, measured in decibels is given by:
I(db)=10log(I/I0)
I is the intensity in MKS units; I0 is the threshold intensity for human hearing (10^-12 W/m^2)
Thus, if the two sounds together have a dB of 81, we know:
81=10log(I/I0)
using the data above, we can find the intensity of the two sounds to be
0.000125 W/m^2
therefore, one firecracker has an intensity half of that, or 0.0000625W/m^2
now use this value to find the dB of one firecracker:
I(dB0=10log(0.0000625/10^-12)=77.96dB
Answer:
D
Explanation:
Unbalanced forces move stuff. Gravity would only increase/decrease movement if the object was already in motion.