Answer:
437500Joules
Explanation:
Kinetic energy=1/2mvsquare
1/2 x 1400 x 25 x25
kinetic energy= 437500Joules
Answer:
Approximately 
.
Assumption: the ball dropped with no initial velocity, and that the air resistance on this ball is negligible.
Explanation:
Assume the air resistance on the ball is negligible. Because of gravity, the ball should accelerate downwards at a constant 
near the surface of the earth.
For an object that is accelerating constantly,
,
where
is the initial velocity of the object,
is the final velocity of the object.
is its acceleration, and
is its displacement.
In this case, is the same as the change in the ball's height: 
. By assumption, this ball was dropped with no initial velocity. As a result, 
. Since the ball is accelerating due to gravity, 
.
.
In this case, would be the velocity of the ball just before it hits the ground. Solve for
.
.
Answer:
The temperature will decrease (get colder).
Explanation:
Enthalpy changes are heat changes accompanying physical and chemical changes. The enthalpy change is the difference between the sum of the heat contents of products and the sum of heat contents of reactants.
- For an endothermic change, heat is absorbed for the reaction.
- The surrounding becomes colder at the end of the reaction and so is the reaction itself.
- The right choice is that the temperature will decrease.
Answer:
Explanation:
speed is define as rate of change of distance or displacement
v=s/t
s=8 m
t=4s
v=8/4
v=2 m/s
Answer: 10Nm or 10J
Explanation:
Given the following :
Force (f) = 5
Distance (d) = 2m
Calculate the kinetic energy assuming no friction
Work done = force × distance
Work done = 5N × 2m = 10Nm
Recall :
Work done = ΔK.E ( change in kinetic energy)
Therefore, kinetic energy of the book after sliding = ΔK. E, which is equal to work done.
Hence, K. E of book after sliding is 10Nm
