Answer:
The answer is "c,d,e, and g".
Explanation:
The correct choices can be defined as follows:
- Higher-frequency microwaves aren't used in any of these systems.
- Infrared waves aren't seen in each of these technologies.
- Its shortest wavelength of all of the technologies listed is the above radiation generated by certain wireless networks.
- These devices all produce waves of wavelengths ranging from 0.10 to 10.0 cm.
Answer:
280 N
Explanation:
Applying Newton's third second law of motion,
F = m(v-u)/t................... Equation 1
Where F = Magnitude of the average force on the ball during contact, v = final velocity of the ball, u = initial velocity of the ball, t = time of contact of the ball and the wall.
Note: Let the direction of the initial velocity of the ball be positive
Given: m = 4 kg, u = 3.0 m/s, v = -4.0 m/s (bounce off), t = 0.1 s
Substitute into equation 1
F = 4(-4-3)/0.1
F = 4(-7)/0.1
F = -28/0.1
F = -280 N.
Note: The negative sign tells that the force on the ball act in opposite direction to the initial motion of the ball
on touching electroscope gets positively charged, so answer is B. conduction
C. Forces have mass and take up space
