Answer:
1

2
The distance is
Explanation:
From the question we are told that
The maximum speed of the cheetah is 
The maximum of gazelle is 
The distance ahead is 
Let
denote the time which the cheetah catches the gazelle
Gnerally the equation representing the distance the cheetah needs to move in order to catch the gazelle is

=> 
=> 
=> 
Now at t = 7.5 s

=> 
=> 
=>
Hence the for the gazelle to escape the cheetah it must be 55.2 m
Answer:
The unbalanced force that caused the ball to stop was friction
Explanation:
As Newton's second law states, the acceleration of an object is proportional to the net force applied on the object:

therefore, in order to move at constant speed, an object should have a net force of zero (balanced forces) acting on it.
In this case, the ball slows down and eventually comes to a stop: it means that the ball is decelerating, so there are unbalanced forces (net force different from zero) acting on it. The unbalanced force acting on the ball is the friction: friction is a force against the motion of the object, which is due to the contact between the surface of the ball and the surface of the street, and this force is responsible for slowing down the ball.
A) 
Let's start by writing the equation of the forces along the directions parallel and perpendicular to the incline:
Parallel:
(1)
where
m is the mass
g = 9.8 m/s^2 the acceleration of gravity

is the coefficient of friction
R is the normal reaction
a is the acceleration
Perpendicular:
(2)
From (2) we find

And substituting into (1)

Solving for a,

B) 5.94 m/s
We can solve this part by using the suvat equation

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
Here we have
v = ?
u = 0 (it starts from rest)

s = 8.70 m
Solving for v,

Answer:
the brightest found are Blue - White with
Explanation:
The energy emission of objects increases with their temperature, specifically Wien described the process in an expression
T = 2,898 10⁻³
With this expression we can find the temperature of the stars by the color they emit.
Specifically the Sun has a color of 550 nm which corresponds to 5400K
bright stars have a BLUE color corresponding to 7500K
the brightest found are Blue - White with a temperature of 20000K