Answer:
1 and 2
Explanation:
It is given that, force exerted by air is negligible in any way.
Also, it is given that channel is in the shape of a segment of a circle with its center at O.
When it is within the frictionless channel at position 'Q',
A gravity exerts force on the ball in the downward direction. On the other hand, the channel pointing from Q to O also exerts a force on the ball.
However, there is no any force in the direction of motion. On the other hand, he channel pointing from O to Q does not exert a force on the ball.
<span>It is the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.
Every planet has their own corresponding escape velocities. Example - Earth has escape velocity of 11.2 Km/s. It means, if you want to leave the Earth's gravitational field then it's the lowest speed which you need to acquire otherwise you wouldn't do that!
Hope this helps!</span>
Answer:
metals, nonmetals, and metalloids.
Explanation:
Answer:
As long as there is rain, a rainbow is possible. Rain is possible on a sunny day, and is known as a sunshower.The rainbow can be observed in a sunny day if the water droplets are present in air and the sun rays pass through it reaches the eye of the observer. In this situation, the observer can see a rainbow.
or
If you happened to look up at the sky this past weekend, you might have noticed a rare and beautiful sight: iridescent rainbow clouds, but not a drop of rain in sight. This phenomenon is known, fittingly, as cloud iridescence or irisation. The effect is not unlike seeing a rainbow painted on the clouds.
The rate of energy radiated by the man is 3.86 x 
J/s. 
.
The amount of energy radiated by an object majorly depends on the area of its surface and its temperature. The is well explained in the Stefan-Boltzmann's law which states that:
Q(t) = Aeσ
where: Q is the quantity of heat radiated, A is the surface area of the object, e is the emmisivity of the object, σ is the Stefan-Boltzmann constant and T is the temperature of the object.
To determine the rate of energy radiated by the man in the given question;
= Aeσ
But A = 1.7 m², e = 0.4 and σ = 5.67 x J/s.
So that;
= 1.7 * 0.4 * 5.67 x
= 3.8556 x
= 3.86 x J/s.
Thus, the rate of energy radiated by the man is 3.86 x J/s. .
Learn more on energy radiation of objects by visiting: brainly.com/question/12550129
