Answer:
<em>The velocity after the collision is 2.82 m/s</em>
Explanation:
<u>Law Of Conservation Of Linear Momentum
</u>
It states the total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and speed v is
P=mv.
If we have a system of two bodies, then the total momentum is the sum of the individual momentums:

If a collision occurs and the velocities change to v', the final momentum is:

Since the total momentum is conserved, then:
P = P'
Or, equivalently:

If both masses stick together after the collision at a common speed v', then:

The common velocity after this situation is:

There is an m1=3.91 kg car moving at v1=5.7 m/s that collides with an m2=4 kg cart that was at rest v2=0.
After the collision, both cars stick together. Let's compute the common speed after that:



The velocity after the collision is 2.82 m/s
1.Record her observation with the time it was hot.
2. Gather info about the pavement and its surroundings. Find out what it's made of and what its temp. is at different times of the day.
3. Come up with a hypothesis about why it is hot.
4. Design an experiment to test the hypothesis. If she thinks the Sun is responsible (which she should b smart enough to know), keep it covered during the day time and check it's temp.
5. Come up with a conclusion. If her hypothesis is not supported, design a new experiment or gather more info.
Answer:
4.163 m
Explanation:
Since the length of the bridge is
L = 380 m
And the bridge consists of 2 spans, the initial length of each span is

Due to the increase in temperature, the length of each span increases according to:

where
is the initial length of one span
is the temperature coefficient of thermal expansion
is the increase in temperature
Substituting,

By using Pythagorean's theorem, we can find by how much the height of each span rises due to this thermal expansion (in fact, the new length corresponds to the hypothenuse of a right triangle, in which the base is the original length of the spand, and the rise in heigth is the other side); so we find:

Answer:
.
Explanation:
Distance Skylar traveled North is 
Then she traveled
Westward.
After which she traveled
towards the South.
The total distance traveled would be the sum of the distances.

The distance traveled by Skylar was is
.
Answer:
20.2 seconds
Explanation:
The airplane (and therefore the crate) initially has no vertical velocity, so v₀ = 0 m/s.
The crate is in free fall, so a = -9.8 m/s².
The crate falls downward, so Δx = -2000 m.
Find: t, the time it takes for the crate to land.
Δx = v₀ t + ½ at²
-2000 m = (0 m/s) t + ½ (-9.8 m/s²) t²
t = 20.2 s
It takes 20.2 seconds for the crate to land.