A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average forc
1 answer:
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Answer:
7.6 s
Explanation:
Considering kinematics formula for final velocity as
Where v and u are final and initial velocities, a is acceleration and s is distance moved.
Making v the subject then
Substituting 8.8 m/s for u, 138 m for s and 2.45 m/s2 for a then
Also, v=u+at and making t the subject of the formula
Substituting 27.45 m/s for v, 8.8 m/s for u and 2.45 m/s for a then
Therefore, it needs 7.6 seconds to travel
Answer:
a) t = 20 [s]
b) Can't land
Explanation:
To solve this problem we must use kinematics equations, it is of great importance to note that when the plane lands it slows down until it reaches rest, ie the final speed will be zero.
a)
where:
Vf = final velocity = 0
Vi = initial velocity = 100 [m/s]
a = desacceleration = 5 [m/s^2]
t = time [s]
Note: the negative sign of the equation means that the aircraft slows down as it stops.
0 = 100 - 5*t
5*t = 100
t = 20 [s]
b)
Now we can find the distance using the following kinematics equation.
x - xo = distance [m]
x -xo = (0*20) + (0.5*5*20^2)
x - xo = 1000 [m]
1000 [m] = 1 [km]
And the runaway is 0.8 [km], therefore the jetplane needs 1 [km] to land. So the jetpalne can't land