Answer:
v = 2 m/s
Explanation:
The object moves 20 m in 10 s initially. Then it remains at rest for 20 s. It is required to find the average speed of the object.
Fro 10 s it covers 20 m. For that time, speed is :

For 20 s, it was at rest means distance covered is 0. So, speed is 0.
The average speed of the object is equal to the sum of speed for 10 s and for 20 s i.e.
v = 2 m/s + 0 = 2 m/s
So, the average speed of the object is 2 m/s.
<span>the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine. I would say the answer is D, but i'm not sure. :)</span>
Answer:
a) No. The kinetic energy of the ball decreases.
b) The potential energy of the ball increases.
c) The ball would go half of the original distance.
Explanation:
a) The kinetic energy would be converted to potential energy as the ball goes higher. Since the total mechanical energy is conserved, the kinetic energy would decrease.
b) The potential energy of the ball would increase. Since the total mechanical energy of the ball is conserved, the ball would lose speed, and therefore kinetic energy. In order to compensate the loss of kinetic energy, the ball would gain potential energy as it goes higher.
c) The relation of the energy and mass is as follows:

According to the energy conservation

The maximum height that the ball reaches is proportional to the initial velocity. If the ball would be imparted with the same amount of energy, its final potential energy would be the same. However, in order to have the same potential energy (mgh), its height would be half of the original case.

The ratio of the deflection when each is connected in turns to a cell of e.m.f 25 V and internal resistance 50 ohms is 13: 12
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What is internal resistance?</h3>
Internal resistance can be described as the resistance within a battery, or other voltage source, that causes a drop in the source voltage when there is a current.
The parameters given are :
Coil 1 = 50 turns
Coil 2 = 500 turns
Resistance 1 = 1022
Resistance 2 = 6002
Internal resistance = 50 ohms
Emf = 25v
I = 25/ 50+ 10
I = 25/60
I = 5/ 12 A
= 25/50+ 600
= 25/ 650
= 5/ 130 A
The ratio of the deflection when each is connected in turns to a cell of e.m. 25 V and internal resistance 50 ohms =
Q1/ Q2
Q1 = N1 x B x
/ c
Q2 = N2 x B x
/ c
therefore Q/ Q2 = (50 x 5/12 )/ (500 x 5/130)
Q1 / Q2 = 12/ 13 which 13: 12
Therefore, The ratio of the deflection when each is connected in turns to a cell of e.m. 25 V and internal resistance 50 ohms is 13: 12.
Learn more about internal resistance at; brainly.com/question/20595977
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this is a link to a web sight with a diagram to help you
https://www.google.com/url?sa=i&source=images&cd=&ved=2ahUKEwjw4v7knNDgAhVyUN8KHWgWD-wQjRx6BAgBEAU&url=%2Furl%3Fsa%3Di%26source%3Dimages%26cd%3D%26ved%3D%26url%3Dhttps%253A%252F%252Ffuturism.com%252Fwhere-do-all-the-elements-come-from%26psig%3DAOvVaw19_FOCuWs_nMsyY1YT0Da-%26ust%3D1550955269844922&psig=AOvVaw19_FOCuWs_nMsyY1YT0Da-&ust=1550955269844922