Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
Answer:
the signal it takes 40 s to get the answer
Explanation:
As the satellite is in space the speed of radiation (waves9 is the speed of light in a vacuum, which is constant 3. 108 m / s, so we can use the uniform motion ratios to find the time.
v = d / t
t = d / v
t = 6.0 109 / 3. 108
t = 2 101 s
t = 20 s
This is the time it takes to get the signal from the earth to the satellite and it takes the same time to return, so since they send the signal it takes 40 s to get the answer
Answer:
The electric force between them if the pieces of grain are 2 cm apart is
.
Explanation:
Given:
Charge on one grain, 
Charge on another grain, 
Separation between them, 
Electric force acting between two charges
separated by a distance
is given as:

Where,
is Coulomb's constant equal to
.
Now, plug in all the values and solve for
.

Therefore, the electric force between them if the pieces of grain are 2 cm apart is
.
Answer:
9.8 times 5?
Explanation:
this is a freefall question so i think that is what it is.
a) x = 
at t = 5s

b) v = 
= 
at t = 5 s
v = 
c) a = 
= 28 - 12t
at t = 5 s
a = 28 -12*5= 28-60= -32 m/
d) At maximum positive coordinate velocity = 0
So, 

At t = 4.66 s

e) At t = 4.66 s
f) At maximum positive velocity a = 0


At t = 2.33 s
V = 
g) t = 2.33 s
h) When particle is not moving v = 0
So 

At t = 4.66 s
a = 
i) At t = 0s, X =0m
t = 5s, X = 100m
So, Displacement = 100m
Velocity = 