Answer:
a) 138.6 m/s
b) 762.3 m
c) 122.3 m/s
d) 24.47
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
Velocity at the end of its upward acceleration is 138.6 m/s
Maximum height the rocket reaches is 762.3 m
The velocity with which the rocket crashes to the Earth is 122.3 m/s
Total time from launch to crash is 12.47+11 = 24.47 seconds
Using the equation
we can observe that you have to apply a non-zero net force to an object in order to make it accelerate. In fact, if the net force is zero you have
Since we're assuming
Now, if the 12N force is applied, the object moves with a constant speed. A constant speed means no acceleration, since by definition the acceleration is a change in speed.
If this sounds counterintuitive to you (why I'm applying a force but I have to acceleration?) think of when we drive a car: even if you want to keep your speed constant, you still have to use the gas pedal, just enough so that the push of the motor balances exactly the road/wheels friction. If you give less gas, the friction becomes stronger, and the car slows down. If you give more gas, the motor push becomes stronger, and the car accelerates.
Back to your exercise: constant speed means to acceleration, so the net force must be zero. This implies that the friction force is exactly 12N.
If the force is increased to 18N, there will be a net force of 6N pushing the object, causing it to accelerate. Using again the same equation of before, and plugging the 3kg mass in the equation, we have
So, the object moves with constant acceleration and initial speed of 10m/s for 0.2 seconds. It's final speed will be
Answer:
true I think
Explanation:
sorry if I'm wrong, have a good day:)
<h2>
Answer: 56.718 min</h2>
Explanation:
According to the Third Kepler’s Law of Planetary motion<em> </em><em>“The square of the orbital period of a planet is proportional to the cube of the semi-major axis (size) of its orbit”.
</em>
In other words, this law states a relation between the orbital period of a body (moon, planet, satellite) orbiting a greater body in space with the size of its orbit.
This Law is originally expressed as follows:
(1)
Where;
is the Gravitational Constant and its value is
is the mass of Mars
is the semimajor axis of the orbit the spacecraft describes around Mars (assuming it is a <u>circular orbit </u>and a <u>low orbit near the surface </u>as well, the semimajor axis is equal to the radius of the orbit)
If we want to find the period, we have to express equation (1) as written below and substitute all the values:
(2)
(3)
(4)
Finally:
This is the orbital period of a spacecraft in a low orbit near the surface of mars