The "objective" (lens or mirror) is the major major major part of
the optical telescope. It's really the only part you need in order
to make a telescope (besides something to hold the objective).
You can put a piece of film or a CCD right at the focal point of
the objective lens or mirror and capture 'images' (pictures) there.
If you want to use the telescope for looking through and seeing stuff
with your eye, then you need the other major part ... the eyepiece lens.
Answer:
C. -12 ab
Explanation:
The restoring force on a spring is given by Hooke's law:

where
k is the spring constant
x is the stretched (or compressed) displacement of the spring
In this problem we have:
k = 4a
x = 3b
Substituting into the equation, we find:

And the negative sign means that the direction of the force (negative) is opposite to the direction of the displacement (positive).
Complete question
A 2700 kg car accelerates from rest under the action of two forces. one is a forward force of 1157 newtons provided by traction between the wheels and the road. the other is a 902 newton resistive force due to various frictional forces. how far must the car travel for its speed to reach 3.6 meters per second? answer in units of meters.
Answer:
The car must travel 68.94 meters.
Explanation:
First, we are going to find the acceleration of the car using Newton's second Law:
(1)
with m the mass , a the acceleration and
the net force forces that is:
(2)
with F the force provided by traction and f the resistive force:
(2) on (1):

solving for a:

Now let's use the Galileo’s kinematic equation
(3)
With Vo te initial velocity that's zero because it started from rest, Vf the final velocity (3.6) and
the time took to achieve that velocity, solving (3) for
:


The required energy to accelerate the golf ball is
.
<h2>What is Energy?</h2>
- Energy, which is observable in the execution of labor as well as in the form of light and heat, is the quantitative quality that is transmitted to an object or to a physical phenomenon in physics.
- Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed.
- The joule, which is defined as "the energy transmitted to an object by the effort of moving it a length of one metre against a force of one newton," is the standard measure for power in the International System of Units (SI).
Given that,
E=
=
=
.
Learn more about energy here:
brainly.com/question/13881533
#SPJ4
Answer:
The value is 
Explanation:
From the question we are told that
The mass of the ice cube is 
The temperature of the ice cube is
The mass of the copper cube is 
The final temperature of both substance is 
Generally form the law of thermal energy conservation,
The heat lost by the copper cube = heat gained by the ice cube
Generally the heat lost by the copper cube is mathematically represented as
![Q = m_c * c_c * [T_c - T_f ]](https://tex.z-dn.net/?f=Q%20%3D%20%20m_c%20%20%2A%20%20c_c%20%2A%20%20%5BT_c%20%20-%20%20T_f%20%5D)
The specific heat of copper is 
Generally the heat gained by the ice cube is mathematically represented as

Here L is the latent heat of fusion of the ice with value 
So

=>
So
=> 