Answer:
F = 4000 N
Explanation:
given,
mass of rocket (M)= 5000 Kg
10 Kg gas burns at speed (m)= 4000 m/s
time = 10 s
average force = ?
at the end the rocket is at rest
by conservation of momentum
M v + m v' = 0
5000 x v - 10 x 4000 = 0
5000 v = 40000
v = 8 m/s
speed of rocket = 8 m/s
now,
we know
change in momentum = F x Δ t


F = 4000 N
Hence, the average force applied to the rocket is equal to F = 4000 N
Answer: 3.41 s
Explanation:
Assuming the question is to find the time
the ball is in air, we can use the following equation:

Where:
is the final height of the ball
is the initial height of the ball
is the initial velocity of the ball
is the time the ball is in air
is the acceleration due to gravity

Then:


Multiplying both sides of the equation by -1 and rearranging:

At this point we have a quadratic equation of the form
, which can be solved with the following formula:
Where:
Substituting the known values:
Solving the equation and choosing the positive result we have:
This is the time the ball is in air
Amplitude is a measurement of the magnitude of displacement (or maximum disturbance) of a medium from its resting state, as diagramed in the peak deviation example below (it can also be a measurement of an electrical signal's increased or decreased strength above or below a nominal state).
Answer:
A star with 15 solar masses is too big to be a main-sequence star.
Answer:
The statement is incorrect because, a force acting on an object does not necessarily have to produce motion.
People have the misconception that when a force acts on an object it always produces motion
Explanation:
The statement is incorrect because, a force acting on an object does not necessarily have to produce motion. It could be in static equilibrium where the net force is zero and produces not motion. The body could also be in dynamic equilibrium when no net force acts on it moving at a constant velocity. But here we are concerned with static equilibrium since the body does not move at all.
People have the misconception that when a force acts on an object it always produces motion and, we have seen from the above tat its not always true.