Answer:
The average recoil force on the gun during that 0.40 s burst is 45 N.
Explanation:
Mass of each bullet, m = 7.5 g = 0.0075 kg
Speed of the bullet, v = 300 m/s
Time, t = 0.4 s
The change in momentum of an object is equal to impulse delivered. So,

For 8 shot burst, average recoil force on the gun is :

So, the average recoil force on the gun during that 0.40 s burst is 45 N.
False, the spinning coil of wire that moves the cone in a speaker does not produces sound.
<u>Explanation</u>:
The wire coil is an electromagnet that is fixed to speaker cone. A normal magnet attached to the back of the speaker cone.When audio is sent in the form of short bursts of electric current to the speaker cone through the wire.
A magnetic field is induced when electric current allowed to pass through the coil. This magnetic field is repelled by the other magnet. This repulsion cause the cone to move forward. In the absence of electric current in the coil, the cone moves backward.
Thus sound waves are produced due to the resulting rarefaction and compression. So it is not the spinning coil of wire but he permanent magnet that produces the sound.
Answer:
R = 0.21 Ω
Explanation:
the formula:
R = r x l/A
R = (44 x 10-⁸ Ωm) x 1.5 / (π x (1 x 10-³ m)²)
R = 6.6 x 10-⁷ / 3.14 x 10-⁶
R = 0.21 Ω
To solve this problem we will use a free body diagram that allows us to determine the Normal Force.
In general, the normal force would be equivalent to

Since the skier is standing on two skis, his weight will be divide by two

Pressure is given as the force applied in a given area, that is

Replacing F with N'


Our values are given as,




Replacing we have that


Therefore the pressure exerted by each ski on the snow is 776.01Pa