Answer:
19.98Joules
Explanation:
Energy possessed by the body is the kinetic energy
Kinetic Energy = 1/2mv²
m is the mass
v is the velocity
For the 4kg moving at 6m/s
kE = 1/2 * 4 * 6^2
KE = 1/2 * 4 * 36
KE = 72Joules
For the 4kg moving at 5.1m/s
kE = 1/2 * 4 * 5.1^2
KE = 1/2 * 4 *26.01
KE = 52.02Joules
Amount of Energy lost = 72 - 52.02
Amount of Energy lost = 19.98Joules
Hence the amount of Energy lost is 19.98Joules
If no frictional work is considered, then the energy of the system (the driver at all positions is conserved.
Let
position 1 = initial height of the diver (h₁), together with the initial velocity (v₁).
position 2 = final height of the diver (h₂) and the final velocity (v₂).
The initial PE = mgh₁ and the initial KE = (1/2)mv₁²
where g = acceleration due to gravity,
m = mass of the diver.
Similarly, the final PE and KE are respectively mgh₂ and (1/2)mv₂².
PE in position 1 is converted into KE due to the loss in height from position 1 to position 2.
Therefore
(KE + PE) ₁ = (KE + PE)₂
Evaluate the given answers.
A) The total mechanical energy of the system increases.
FALSE
B) Potential energy can be converted into kinetic energy but not vice versa.
TRUE
C) (KE + PE)beginning = (KE + PE) end.
TRUE
D) All of the above.
FALSE
Answer:
13.5 ms
Explanation:
The sound wave travels with uniform motion in both cases, so the time taken to cover a distance d is given by:
where
d is the distance to cover
v = 340 m/s is the speed of sound in air
So for the people across the newsroom,
d = 4.7 m
So the time taken is
The radio waves instead travels with uniform motion at the speed of light:
So the time taken for them is
where
d = 82 km = 82,000 m
is the distance of the people who are 82 km away. Substituting,
Therefore, the difference in time is
Answer:
Both pairs have four pairs of perpendicular sides.
Explanation:
A rectangle and a square both have four right angles and four perpendicular lines.