Answer:
Surface area of the dog is changes from A to 3A
Explanation:
It is given that surface area of dog is increased by factor 3 in a period of 4 year
We have to find the change in dog's relative surface area in the given time period
Let initially the surface area is A
As the surface area is increased by a factor of 3
So surface area after 4 year = 3×A = 3A
So surface area of the dog is changes from A to 3A
The complete question is;
James Joule (after whom the unit of energy is named) claimed that the water at the bottom of Niagara Falls should be warmer than the water at the top, 51 m above the bottom. He reasoned that the falling water would transform its gravitational potential energy at the top into thermal energy at the bottom, where turbulence brings the water almost to a halt. If this transformation is the only process occurring, how much warmer will the water at the bottom be?
Answer:
Water becomes warmer by a temperature of ΔT = 0.119 K
Explanation:
If we assume that gravitational kinetic energy will be converyrf into thermal enrgy, we will have;
Q = U
So, m•c_w•ΔT = mgh
Where;
c_w is specific heat capacity of water with a value of 4184 J/Kg.K
ΔT is change in temperature indicating how warmer the water will be. Thus making ΔT the subject, we have;
ΔT = gh/c_w
So, ΔT = 9.8 x 51/4184 = 0.119 K
There are a few disadvantages, so let's start with the most simple. Night time, the sun isn't up so solar panels can't gather energy. Also, when it's snowing or raining or it's cloudy. Another thing is as of right now it's costly to get solar panels installed. Furthermore, a solar panel has to be maintained as in brushed cause debris can get caught on it and therefore block the sunlight. If you have anymore questions just comment and I will help further. I hope this helps!
D is definitely the correct choice here.
I think a case could also be made for choice-B, but that would be a tough, complex operation.
Complete question:
The length of nylon rope from which a mountain climber is suspended has an effective force constant of 1.40 ×10⁴ N/m.
What is the frequency (in Hz) at which he bounces, given that his mass plus the mass of his equipment is 84.0 kg?
Answer:
The frequency (in Hz) at which he bounce is 2.054 Hz
Explanation:
Given;
effective force constant, K = 1.40 ×10⁴ N/m.
The total mass = his mass plus the mass of his equipment, m = 84 kg
The frequency (in Hz) at which he bounce is given by;
Therefore, the frequency (in Hz) at which he bounce is 2.054 Hz