Answer:
work accomplished = 300*30
= 9,000 J
applied work = 9,000 + 2,000 = 11,000 Joules
efficiency = 100 * work accomplished/work applied
= (9/11)100 = 81.8 %
force applied = (300/6)/.818
= 61.1 N
assuming that the 6 in your question refers to mechanical advantage
Sound waves requires a medium (material) to vibrate in order to produce a sound. So sound waves cannot travel in outer space as it is vacuum.
Answer:
Maximum height of rocket = 2538.74 m
Explanation:
We have equation of motion s = ut + 0.5 at²
For first 5 seconds
s = 0 x 5 + 0.5 x 40 x 5² = 500 m
Now let us find out time after 5 seconds rocket move upward.
We have the equation of motion v = u + at
After 5 seconds velocity of rocket
v = 0 + 40 x 5 = 200 m/s
After 5 seconds the velocity reduces 9.8m/s per second due to gravity.
Time of flying after 5 seconds

Distance traveled in this 20.38 s
s = 200 x 20.38 - 0.5 x 9.81 x 20.38² = 2038.74 m
Maximum height of rocket = 500 +2038.74 = 2538.74 m
Answer:
9.4 m/s
Explanation:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in kinetic energy of the system.
Therefore we can write:

where in this case:
W = -36,733 J is the work done by the parachute (negative because it is opposite to the motion)
is the initial kinetic energy of the car
is the final kinetic energy
Solving,

The final kinetic energy of the car can be written as

where
m = 661 kg is its mass
v is its final speed
Solving for v,

The answer would be A. As the bat is swung, it gains kinetic energy. But once it hits the ball, it loses, or transfers, it’s kinetic energy to the ball.