The brown hair for sure :)
Answer:
Weight required = 194.51 N
Explanation:
The elongation is given by
Length , L= 1.6 m
Diameter, d = 1.1 mm
Area
Change in length, ΔL = 2.8 mm = 0.0028 m
Young's modulus of copper, E = 117 GPa = 117 x 10⁹ Pa
Substituting,
Weight required = 194.51 N
Water is a really good conductor of sound so I would have to say that it would be to send the message underwater because a more dense medium produces a louder sound
Answer:
the awnser to the question is Is C
Answer:
The block+bullet system moves 4 m before being stopped by the frictional force.
Explanation:
Using the law of conservation of llinear momentum and the work energy theorem, we can obtain this.
According to Newton's second law of motion
Momentum before collision = Momentum after collision
Momentum before collision = (0.02×400) + 0 (stationary block)
Momentum before collision = 8 kgm/s
Momentum after collision = (2+0.02)v
8 = 2.02v
v = 3.96 m/s.
According to the work-energy theorem,
The kinetic energy of the block+bullet system = work done by Friction to stop the motion of the block+bullet system
Kinetic energy = (1/2)(2.02)(3.96²) = 15.84 J
Work done by the frictional force = F × (distance moved by the force)
F = μmg = 0.2(2.02)(9.8) = 3.96 N
3.96d = 15.84
d = (15.84/3.96) = 4 m
