Explanation:
Given that,
Object-to-image distance d= 71 cm
Image distance = 26 cm
We need to calculate the object distance


We need to calculate the focal length
Using formula of lens

put the value into the formula



The focal length of the lens is 35.52.
(B). Given that,
Object distance = 95 cm
Focal length = 29 cm
We need to calculate the distance of the image
Using formula of lens

Put the value in to the formula




We need to calculate the magnification
Using formula of magnification



The magnification is 0.233.
The image is virtual.
Hence, This is the required solution.
A 100kg crate slides along a floor with a starting velocity of 21 m/s. If the force due to friction is 8N, then, it will take 262.5 s for the box to come to rest.
We'll begin by calculating the declaration of the box. This can be obtained as follow:
Force (F) = –8 N (opposition)
Mass (m) = 100 Kg
<h3>Deceleration (a) =? </h3>
<h3>F = ma</h3>
–8 = 100 × a
Divide both side by 1000

<h3>a = –0.08 ms¯²</h3>
Therefore, the deceleration of the box is –0.08 ms¯²
Finally, we shall determine the time taken for the box to come to rest. This can be obtained as follow:
Deceleration (a) = –0.08 ms¯²
Initial velocity (u) = 21 ms¯¹
Final velocity (v) = 0 ms¯¹
<h3>Time (t) =.? </h3>
<h3>v = u + at</h3>
0 = 21 + (–0.08×t)
0 = 21 – 0.08t
Collect like terms
0 – 21 = –0.08t
–21 = –0.08t
Divide both side by –0.08

<h3>t = 262.5 s</h3>
Therefore, it will take 262.5 s for the box to come to rest.
Learn more: brainly.com/question/14446351
Answer: C. Metal transfers heat away from the skin by conduction, creating the sensation of coolness.
Explanation: The skin releases heat into the metal bowl since there is a difference in temperature between the two objects. So heat is taken away from the hand abd transfers into the metal bowl by conduction creating a cooler sensation.
B. five electrons
If you want an explanation, here it is.
The atomic number gives the number of protons. Protons which have a positive charge are balanced by an equal number of electrons in a neutral atom. Boron number 5 has five protons and therefore as a neutral atom also has five electrons.