
The ball is against the vector of gravity. Then, the gravity will be negative.

The ball will stop in the air after approx. 4.72 seconds. And will take the same time to hit the ground.
It will stay approx. 9.44 seconds in the air.
Answer:
0
Explanation:
Assuming your graph and question match the attachment, the average speed is 0. The bug ends up where it started, so its displacement is zero.
average speed = displacement/time = 0/(8 s)
average speed = 0
Question 1:
Answer:
The moment of inertia of Alex's rolling hoop is 0.197 
Explanation:
<u>Given</u>:
Mass of the hoop = 0.350 g
Radius of the hoop = 75.0 cm
<u>To Find:</u>
The moment of inertia of Alex's rolling hoop = ?
<u>Solution</u><u>:</u>
The moment of inertia = 
where
m is the mass
r is the radius
Converting cm to m, we get
75.0 cm = 0.75 m
Now substituting the values,
=> moment of inertia = 
=> moment of inertia = 
=> moment of inertia = 
Question 2:
Answer:
The combined angular momentum of the masses is 1.76 
If she pulls her arms in to 0.12 m, her new linear speed is 
Explanation:
Given:
Mass = 2.0 kg
Radius = 0.8 m
Velocity = 1.2 m/s
a.The combined angular momentum of the masses:

Substituting the values,

L= 1.76 
b. If she pulls her arms in to 0.12 m, what is her new linear speed




Answer:
To increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.
Explanation:
First, we have to calculate the work function of the element. The maximum kinetic energy as a function of the wavelength is given by:

Here h is the Planck's constant, c is the speed of light,
is the wavelength of the light and W the work function of the element:

Now, we calculate the wavelength for the new maximum kinetic energy:

This wavelength corresponds to ultraviolet radiation. So, to increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.