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.
C. Volcanoes above subduction zones have lava that is not basaltic.
Answer:
Gasoline will float
Asphalt will sink
Cork will float
Explanation:
Simply compare the value of each object's density to that of the sea water (1.025 g/ml). If the density of the object is less than that of the water, the object will float due to the buoyance force.
Contrarily, if the density of the object is larger than that of sea water, the object will sink.
Gasoline, with density 0.66 g/ml which is less than that of sea water, will float.
Gasoline, with density 1.2 g/ml which is more than that of sea water, will sink.
Cork, with density 0.26 g/ml which is less than that of sea water, will float.
A change in internal energy causes work to be done and heat to flow into the system
Answer:
Explanation:
we use the equation for the final speed:
where 
is the final speed, 
is the initial speed, 
is the gravitational acceleration (
) and 
is the height.
In this case we don't have an initial velocity indicated so: 
, and we are told that the boulder is at a height: 
.
We substitute this values into the equation:
the speed of the object right before it hits the ground is
