Answer:
The magnification of an astronomical telescope is -30.83.
Explanation:
The expression for the magnification of an astronomical telescope is as follows;

Here, M is the magnification of an astronomical telescope,
is the focal length of the eyepiece lens and
is the focal length of the objective lens.
It is given in the problem that an astronomical telescope having a focal length of objective lens 74 cm and whose eyepiece has a focal length of 2.4 cm.
Put
and
in the above expression.

M=-30.83
Therefore, the magnification of an astronomical telescope is -30.83.
Answer:
4.5 s, 324 ft
Explanation:
The object is projected upward with an initial velocity of

The equation that describes its height at time t is
(1)
where t, the time, is measured in seconds.
In order to find the time it takes for the object to reach the maximum height, we must find an expression for its velocity at time t, which can be found by calculating the derivative of the position, s(t):
(2)
At the maximum heigth, the vertical velocity is zero:
v(t) = 0
Substituting into the equation above, we find the corresponding time at which the object reaches the maximum height:

And by substituting this value into eq.(1), we also find the maximum height:

Answer:
If F is a constant, we can take f = 1
f = m×a
ma = 1
therefore we can say that force is hence proportinal to the product of mass and acceleration.
Answer:
<em>The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
<em></em>
Explanation:
Let us first consider the initial characteristics of the angular motion of the disk
moment of inertia = 
angular speed = ω
For the second case, we consider the characteristics to now be
moment of inertia =
(five times larger)
angular speed = ω/5 (five times smaller)
Recall that the kinetic energy of a spinning body is given as

therefore,
for the first case, the K.E. is given as

and for the second case, the K.E. is given as


<em>this is one-tenth the kinetic energy before its spinning characteristics were changed.</em>
<em>This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>