Answer:
The instantaneous velocity is the specific rate of change of position (or displacement) with respect to time at a single point (x,t) , while average velocity is the average rate of change of position (or displacement) with respect to time over an interval.Average velocity : Average velocity of a body is defined as the change in position or displacement (Δx) divided by time interval (Δt) in which that displacement occurs.
Instantaneous velocity : The instantaneous velocity of a body is the velocity of the body at any instant of time or at any point of its path .
velocity can be positive , negative or zero.
By studying speed and velocity we come to the result that at any time interval average speed of an object is equal or more than the average but instantaneous speed is equal to instantaneous velocity.
 
        
             
        
        
        
Answer:
Density of unknown liquid is 
Explanation:
When rock is suspended in air then the weight of the rock is counter balanced by the tension force in the string
So here we have

now when the rock is immersed in water then the tension in the string is and buoyancy force due to water is counter balanced by the weight of the object
so here we have



now we have


now when the rock is immersed into other liquid then we have



now we have


 
        
             
        
        
        
Answer:
J for impulse
t for time
F for force 
formula is J=F×t
Explanation:
putting values in eqs after rearranging
we need to find force so
F=J ÷t
F=400÷15
=26.67
=27(rounded off)
27N is the Force applied.
 
        
             
        
        
        
Answer:
La rapidez con que el fármaco es absorbido en el torrente sanguíneo depende, en parte, del suministro de sangre al músculo: cuanto menor sea el aporte de sangre, más tiempo necesitará el fármaco para ser absorbido.
Para la administración por vía intravenosa se inserta una aguja directamente en una vena
Explanation: