Answer:
The answer is D, hope you past!
Explanation:
Answer:
B. 3 m/s
Explanation:
We can solve the problem by using the law of conservation of momentum; in fact, the total momentum before and after the collision must be conserved. So we can write:
where:
m1 = 150 kg is the mass of spaceship 1
m2 = 150 kg is the mass of spaceship 2
u1 = 0 m/s is the initial velocity of spaceship 1
u2 = 6 m/s is the initial velocity of spaceship 2
v is the velocity of the two ships after they collide and stick together
Solving for v, we find:
Answer: fourth option) <span>the change in the height of a liquid in a tube that is open on one end
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Justification:
When the tube is open the liquid in it is subject to changes in atmosphere pressure, so it cannot not be reliable, because the depending on the weather conditoins and the altitude of the place, the measurement would differ.
The thermometers have to be closed so that the changes in the liquid expansion reflects only the change in temperature.
Note that the other two phenomena (change in pressure of a gas and change in resistances of metals) are very well related to changes in temperature and, so, devices based on them would result in precise temperature measurement devices.
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Answer:
The object will travel 675 m during that time.
Explanation:
A body moves with constant acceleration motion or uniformly accelerated rectilinear motion (u.a.r.m) when the path is a straight line, but the velocity is not necessarily constant because there is an acceleration.
In other words, a body performs a u.a.r.m when its path is a straight line and its acceleration is constant. This implies that the speed increases or decreases uniformly.
In this case, the position is calculated using the expression:
x = xo + vo*t + ½*a*t²
where:
- x0 is the initial position.
- v0 is the initial velocity.
- a is the acceleration.
- t is the time interval in which the motion is studied.
In this case:
- x0= 0
- v0= 0 because the object is initially stationary
- a= 6
- t= 15 s
Replacing:
x= 0 + 0*15 s + ½*6 *(15s)²
Solving:
x=½*6 *(15s)²
x=½*6 *225 s²
x= 675 m
<u><em>
The object will travel 675 m during that time.</em></u>
When the box IS on the shelf 2m above the ground,
its potential energy is
(weight) x (height) = (3 N) x (2 m) = 6 joules .
THAT's the work you have to do, to lift the box up to there.