Answer: 16.3 seconds
Explanation: Given that the
Initial velocity U = 80 ft/s
Let's first calculate the maximum height reached by using third equation of motion.
V^2 = U^2 - 2gH
Where V = final velocity and H = maximum height.
Since the toy is moving against the gravity, g will be negative.
At maximum height, V = 0
0 = 80^2 - 2 × 9.81 × H
6400 = 19.62H
H = 6400/19.62
H = 326.2
Let's us second equation of motion to find time.
H = Ut - 1/2gt^2
Let assume that the ball is dropped from the maximum height. Then,
U = 0. The equation will be reduced to
H = 1/2gt^2
326.2 = 1/2 × 9.81 × t^2
326.2 = 4.905t^2
t^2 = 326.2/4.905
t = sqrt( 66.5 )
t = 8.15 seconds
The time it will take for the rocket to return to ground level will be 2t.
That is, 2 × 8.15 = 16.3 seconds
A Atom is the basic unit of each type of element
Answer:
The shortest distance in which you can stop the automobile by locking the brakes is 53.64 m
Explanation:
Given;
coefficient of kinetic friction, μ = 0.84
speed of the automobile, u = 29.0 m/s
To determine the the shortest distance in which you can stop an automobile by locking the brakes, we apply the following equation;
v² = u² + 2ax
where;
v is the final velocity
u is the initial velocity
a is the acceleration
x is the shortest distance
First we determine a;
From Newton's second law of motion
∑F = ma
F is the kinetic friction that opposes the motion of the car
-Fk = ma
but, -Fk = -μN
-μN = ma
-μmg = ma
-μg = a
- 0.8 x 9.8 = a
-7.84 m/s² = a
Now, substitute in the value of a in the equation above
v² = u² + 2ax
when the automobile stops, the final velocity, v = 0
0 = 29² + 2(-7.84)x
0 = 841 - 15.68x
15.68x = 841
x = 841 / 15.68
x = 53.64 m
Thus, the shortest distance in which you can stop the automobile by locking the brakes is 53.64 m
The correct option is (b) 5n
As a result, there is a net downward force of 5N operating on the object.
The resultant force is the force that results from adding the vector sums of all the forces operating on an item. The combined action of all the acting forces on the object produces the same effect as the resulting force. When determining the resulting force, the direction of the forces must be taken into account.
Given;
The northward force is Fn = 10N
The southward force is Fs = 15N
Required;
The net force on the mobile phone is Fnet = ?N
The object's weight exerts downward pressure, and upward resistance exerts upward pressure. The vector sum of these two forces will be the net force.
Fnet = Fs - Fn (Considering the direction downward as positive)
Fnet= 15N - 10N
Fnet = 5N
As a result, there is a net downward force of 5 N operating on the object.
Learn more about the Force with the help of the given link:
brainly.com/question/7362815
#SPJ4
<span>A: put an atom on a poster in the exhibit
Good luck. The poster itself is made of trillions of trillions of trillions
of atoms. You could not see the extra one any easier than you could
see the ones that are already there, and even if you could, it would be
lost in the crowd.
B: use a life size drawing of an atom
Good luck. Nobody has ever seen an atom. Atoms are too small
to see. That's a big part of the reason that nobody knew they exist
until less than 200 years ago.
D: set up a microscope so that visitors can view atoms
Good luck. Atoms are way too small to see with a microscope.
</span><span><span>C: Display a large three dimensional model of an atom.
</span> </span>Finally ! A suggestion that makes sense.
If something is too big or too small to see, show a model of it
that's just the right size to see.
