Answer:
Yeah it's ok I think. Also, I can't see the answer you gave so maybe updating the question would be nice.
Answer:
The slope of the position time graph gives the velocity.
Explanation:
The slope of the position time graph gives the value of velocity.
In first graph,
The slope is constant in both the parts but positive . So the velocity is also constant and positive for both the parts. and more than the second part, so the initial velocity is more than the final velocity.
In the second graph,
The slope is constant in both the parts but negative. So, the velocity is constant but negative for both the parts. Initial velocity is more negative than the final velocity.
Answer: "One object speeds up before it slows to a stop
"
(the top one)
Explanation:
Ok, first a little recall on how to read this type of graph.
If the points are far apart, the object is moving fast.
If the points are close together, the object is moving slow.
If the distance between the points changes then the velocity of the object changes, which means that the object is accelerated.
If we have a lot of points clustered in one location, then the object is not moving.
We can see:
The top object starts slow, then it increments the speed, then it slows down again, and then it comes to stop.
The bottom object starts fast, and it slows down.
then:
"One object speeds up before it slows to a stop
"
This describes the motion of the top object, this is the only correct option that describes one of the graphs.
Answer:
For the bird moving in a straight line, the kinetic energy is one-half the product of the mass and the square of the speed: Ek=12mu2.
Answer:
259.274 kW
Explanation:
Given:
Area of the lava, A = 1.00 m²
Temperature of the surrounding, T₁ = 30.0° C = 303 k
Temperature of the lava, T₂ = 1190° C = 1463 K
emissivity, e = 1
Now,
from the Stefan-Boltzmann law of radiation the rate of heat loss is given as,
u = σeA(T₂⁴ - T₁⁴)
where,
u = rate of heat loss
σ = Stefan-Boltzmann constant = 5.67 × 10⁻⁸ W/m²∙K⁴
on substituting the respective values, we get
u = 5.67 × 10⁻⁸ × 1 × 1 × (1463⁴ - 303⁴)
or
u = 259274.957 W
or
u = 259.274 kW
