It is a chemical change and a physical change
        
             
        
        
        
Answer:
The magnitude of the horizontal displacement of the rock is 7.39 m/s.
Explanation:
Given that,
Initial speed = 11.5 m/s
Angle = 50.0
Height = 30.0 m
We need to calculate the horizontal displacement of the rock
Using formula of horizontal component

Put the value into the formula


Hence, The magnitude of the horizontal displacement of the rock is 7.39 m/s.
 
        
             
        
        
        
A). It takes air in from outside the body.
        
             
        
        
        
Answer:
Factories contribute to air and water pollution.
Explanation:
 
        
             
        
        
        
U need to set up n solve the general eqn for simple harmonic motion:
x" = -(k/m)x
solution is x(t) = (x0)*cos(wt) + (v0/w)*sin(wt)
where w=sqrt(k/m), x0 is x-position at t=0 and v0 is vel at t=0
u already calculated f in Q.2 and w = 2*pi*f
x0 is 0 as it starts at eqm
v0 is given at 5.1
so u have x(t)
vel is given by x'(t) = (x0)*(-w)*sin(wt) + (v0/w)*w*cos(wt)
substitute t=0.32, x0=0, v0=5.1 n w in the above, u can solve for v at t=0.32.