I’ve done this before the answer is B
        
             
        
        
        
The answer is "156.6 m/s".
This is how we calculate this;
-N + mg = ma = mv²/r
For "weightlessness" N = 0, so
0 = mg - mv²/r 
g - v²/r = 0 
v =√( gr) 
g = 9.8 and r = 2.5km = 2500 m
v = √(9.8 x 2500)
= 156.6 m/s
        
             
        
        
        
Answer:
The answer to your question is 1800 Pa
Explanation:
Data
Weight = 2700 N
Area = 1.5 m²
Pressure = ?
Formula
Pressure = Force / Area
The Pressure is defined as the force exerted per unit area.
-Substitution
  Pressure = 2700 / 1.5
-Result 
  Pressure = 1800 Pa
The units of pressure are Pascals (Pa)
 
        
             
        
        
        
Answer:
The length of cable is 12.5 m
Explanation:
Since, the wrecking ball completes 1 oscillation, in the same time, as it takes for the rock to complete 5 oscillations.
Therefore,
Time Period of Wrecking Ball = 5 (Time Period of Rock)
Since,
Time Period of  Pendulum = 2π√(L/g)
Therefore,
2π√(L₁/g) = 5[2π√(L₂/g)]
√L₁ = 5√L₂
Squaring on both sides:
L₁ = 25 L₂
where,
L₁ = Length of Cable = ?
L₂ = Length of string = 0.5 m
Therefore,
L₁ = 25 (0.5 m)
<u>L₁ = 12.5 m</u>