I can answer it in the comments, but can i ask what i’m supposed to do exactly? i remember learning about this stuff but i need the instructions.
Answer: Part(a)=0.041 secs, Part(b)=0.041 secs
Explanation: Firstly we assume that only the gravitational acceleration is acting on the basket ball player i.e. there is no air friction
now we know that
a=-9.81 m/s^2 ( negative because it is pulling the player downwards)
we also know that
s=76 cm= 0.76 m ( maximum s)
using kinetic equation

where v is final velocity which is zero at max height and u is it initial
hence


now we can find time in the 15 cm ascent


using quadratic formula

t=0.0409 sec
the answer for the part b will be the same
To find the answer for the part b we can find the velocity at 15 cm height similarly using

where s=0.76-0.15
as the player has traveled the above distance to reach 15cm to the bottom


when the player reaches the bottom it has the same velocity with which it started which is 3.861
hence the time required to reach the bottom 15cm is

t=0.0409
Answer:
3675 J
Explanation:
Gravitational Potential Energy =
× mass × g × height
( g is the gravitation field strength )
Mass = 50 kg
G = 9.8 N/kg ( this is always the same )
Height = 15 m
Gravitational Potential Energy =
× 50 ×9.8 × 15
= 3675 J
Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
That is true imo not false