Answer:
Explanation:
This problem is an example of a perfectly inelastic collision. After the collision, the two cars merge into a single object. So in order to find the velocity of that object, we need to find the velocity of the center of mass of the given system of 2 cars.
Mass of Ford = = 2080 kg
Mass of truck = = 18400 kg
Velocity of Ford = = 22.6 m/s north
Velocity of truck = = 10.4 m/s east
Let us break up the velocity vector into 2 components, one along north () and one along east ().
Therefore,
(speed of truck along the north is zero)
Similarly,
(speed of Ford along the east is zero)
Hence, the resultant speed of the entangled cars is given by,
and the direction is given by (please refer to the figure attached),
The post-collision speed and direction of the two entangled vehicles, calculated using principles of momentum conservation and trigonometry, are found to be 9.82 m/s and 76.4 degrees east of north respectively.
In this scenario, we are dealing with the principles of momentum conservation. In a collision like this one, the total momentum before the collision equals the total momentum after the collision, as long as no external forces are acting on the system. The momentum (p) of an object is calculated as the mass (m) of the object multiplied by its velocity (v), or p=mv.
Before the collision, the total momentum of the system (ptotal) is the sum of the momentum of the Ford Explorer (pExplorer) and the garbage truck (ptruck). After the collision, they move together as a single object, so their combined mass and velocity would make up the total momentum.
Based on the given information, pExplorer = 2080 kg * 22.6 m/s = 47,008 kg*m/s and ptruck = 18400 kg * 10.4 m/s = 191,360 kg*m/s. The direction should also be taken into account. Since they are perpendicular to each other, we can use the Pythagorean Theorem to find the resultant momentum: (pExplorer)^2 + (ptruck)^2 = ptotal^2, which gives a total momentum of 201,262.8 kg*m/s.
Now, the total mass (mtotal) of two entangled vehicles is 2080 kg + 18400 kg = 20480 kg. Hence the velocity (v) of the two vehicles after the collision is calulated by ptotal divided by mtotal : 201262.8 kg*m/s / 20480 kg = 9.82 m/s. The direction is calculated using trigonometrics such as tan(-1)(ptruck / pExplorer) which gives a direction of 76.4 degrees east of north.
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temperature is the answer
How high up must the 7th floor be?
If you had thrown it at the same speed but at the 28th floor, how far from the base of the building would it land?
1) 31.1 m/s
The rock has been thrown straight out of the window: its motion on the horizontal direction is simply a uniform motion, with constant speed , because no forces act in the horizontal direction. The speed in a uniform motion is given by
where S is the distance traveled and t the time taken.
In this case, the distance by the rock before hitting the ground is and the time taken is , so the initial speed is given by
2) 67.1 m
In this part of the problem we are only interested in the vertical motion of the rock. The vertical motion is a uniformly accelerated motion, with constant acceleration (acceleration of gravity) towards the ground. In a uniformly accelerated motion, the distance traveled by the object is given by
where t is the time. Substituting a=9.8 m/s^2 and t=3.7 s, we can find S, the vertical distance covered by the rock, which corresponds to the height of the 7th floor:
3) 230.1 m
The height of the 7th floor is 67.1 m. So we can assume that the height of each floor is
And so, the height of the 28th floor is
We can find the total time of the fall in this case by using the same formula of the previous part:
In this case, S=268.8 m, so we can re-arrange the formula to find t
And now we can consider the motion of the rock on the horizontal direction: we know that the rock travels at a constant speed of v=31.1 m/s, so the distance traveled is
And this is how far from the building the rock lands.