Answer:
a. 1.64 m/s²
Explanation:
Centripetal acceleration is the square of tangential velocity divided by the radius.
a = v²/r
First, convert km/h to m/s.
30.0 km/h (1000 m/km) (1 h / 3600 s) = 8.33 m/s
Find the acceleration.
a = (8.33 m/s)² / (42.4 m)
a = 1.64 m/s²
Answer: 4 s
Explanation:
Given
The applied force is 70 N
mass of the rock is 28 kg
initial velocity 
final velocity 
Deceleration provided by force is
using the equation of motion
Its speed reading would increase to 10 m/s every second
If you multiply m (the unit for wavelength) with 1s (the unit for frequency), you will get m/s, the unit for speed. Now multiply! 25 m/s is your final answer!
The correct answer is A. Most reactive non metals.
Firstly if some one knows how to read the periodic table he would have no confusion in deciding whether group 7 has metals or non metals. Group 7 contains non metals so basically we can easily cancel out two options of metals.
Secondly group 7 non metals are the most reactive non metals as they need only one electron in order to complete their valence shell and become stable.
