Answer:
-39.2m/s
Explanation:
Using the equation of motion;
v = u + at
Since the ball is thrown upward, the acceleration due to gravity acting on it will be negative, hence a = -g
v = u - gt
Since g = 9.8m/s²
t = 4.0s
u = 0m/s
v = 0 + (-9.8)(4)
v = 0 + (-9.8)(4)
v = -39.2m/s
Hence the speed of the ball before release is -39.2m/s
D. Is repelled by a magnet
The total power emitted by an object via radiation is:

where:
A is the surface of the object (in our problem,


is the emissivity of the object (in our problem,

)

is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is

Substituting these values, we find the power emitted by radiation:

So, the correct answer is D.
Answer:
Explanation:
From the given information:
Let the first weight be
= 80 kg
The weight of the buddy be
= 120 kg
The weight of Bubba be
= 60 kg
Also, since you and Budda are a distance of 4m to each other, then the length to which both meet buddy will be:

The length of the boat be
= 4 m
∴
We can find the center of mass of the system by using the formula:

It is not possible to see the other waves on the electromagnetic spectrum because only other species can see the other parts of the spectrum because they have different components in their eyes than we do, therefore, only allowing us to see a
portion of the spectrum, which is visible light.