<span>B. It stays the same</span>
Answer:
B. 6 cm
Explanation:
First, we calculate the spring constant of a single spring:
where,
k = spring constant of single spring = ?
F = Force Applied = 10 N
Δx = extension = 4 cm = 0.04 m
Therefore,
Now, the equivalent resistance of two springs connected in parallel, as shown in the diagram, will be:
For a load of 30 N, applying Hooke's Law:
Hence, the correct option is:
<u>B. 6 cm</u>
Answer: Both cannonballs will hit the ground at the same time.
Explanation:
Suppose that a given object is on the air. The only force acting on the object (if we ignore air friction and such) will be the gravitational force.
then the acceleration equation is only on the vertical axis, and can be written as:
a(t) = -(9.8 m/s^2)
Now, to get the vertical velocity equation, we need to integrate over time.
v(t) = -(9.8 m/s^2)*t + v0
Where v0 is the initial velocity of the object in the vertical axis.
if the object is dropped (or it only has initial velocity on the horizontal axis) then v0 = 0m/s
and:
v(t) = -(9.8 m/s^2)*t
Now, if two objects are initially at the same height (both cannonballs start 1 m above the ground)
And both objects have the same vertical velocity, we can conclude that both objects will hit the ground at the same time.
You can notice that the fact that one ball is fired horizontally and the other is only dropped does not affect this, because we only analyze the vertical problem, not the horizontal one. (This is something useful to remember, we can separate the vertical and horizontal movement in these type of problems)
Answer:
h = 2.49 [m]
Explanation:
In order to solve this problem we must use the definition of potential energy, which tells us that energy is equal to the product of mass by gravity by height.
The potential energy can be calculated by means of this equation:
Ep = m*g*h
where:
Ep = potential energy = 980 [J]
m = mass = 40 [kg]
g = gravity acceleration = 9.81 [m/s^2]
h = elevation [m]
Now replacing:
980 = 40*9.81*h
h = 2.49 [m]
Answer:
Moment of inertia = 0.3862kg-m²
Explanation:
2.00x10³
2.80cm
145 rad
r = r⊥ x F
F is an applied force
r⊥ is the distance between the applied force and axis
Force exerted = 2.00x10³
r⊥ = 2.8cm = 0.028m
Alpha = 145rad/s²
r = 0.028m x 2.00x10³
r = 56.0N-m
To get the moment of inertia
56.0N-m² = (145rad/s²) x I
The I would be:
I = (56.0N-m²)/(145rad/s²)
I = 56/145
= 0.3862Kg-m²
This is the moment of inertia.
Thank you!
