Answer:
Density is the mass to volume ratio of an object.
> It tells you how compact the mass is.
> Density = mass/volume
The density of water is 1 g/ml or 1 kg/L or 1000 kg/m3
• If an object has a density less than that of water, it
will float.
• If an object has a density more than that of water, it
will sink
Explanation:
hope this helps some
 
        
                    
             
        
        
        
Answer:
a) 

b) 
Explanation:
The net force on the car must produce the centripetal acceleration necessary to make this circle, which is  . At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):
. At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):

Which means:

The limit for falling off would be  , so the minimum speed would be:
, so the minimum speed would be:

 
        
             
        
        
        
Answer:
The force exerted by the floor is 80 N.
Explanation:
Given that,
Mass of ball = 0.5 kg
Velocity= 4 m/s
Time t = 0.05 s
When the ball rebounds then the kinetic energy is

Where, m = mass of ball
v = velocity of ball
Put the value into the formula


The average force exerted by the floor on the ball = change in kinetic energy over collision time


Hence, The force exerted by the floor is 80 N.
 
        
             
        
        
        
For an object that travels at a fixed speed along a circular path, the acceleration of the object is LARGER IN MAGNITUDE THE SMALLER THE RADIUS OF CIRCLE.
        
                    
             
        
        
        
The kinetic energy of any moving object is
                           (1/2) (mass) (speed²) .
For the object you described, that's
                            (1/2) (100 kg) (12.5 m/s)²
                         =      (50 kg)  (156.25 m²/s²)
                         =              7,812.5 joules  
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Your attachment is way out of focus, and impossible to read.