The US Department of Energy has set its own targets to achieve 15% of the country's electricity from hydropower by 2030 — it is currently 7%. Elsewhere around the world, countries are pledging to meet more and more of their energy needs through renewable energy sources.
Answer:
Rococo art relates to an artistic style especially of the 18th century characterized by fanciful curved asymmetrical forms and elaborate ornamentation.
Explanation:
yes
Answer:
The decided by staring at and observing the stars.
Explanation:
Answer:
C. Both a and b
Explanation:
Firstly, persons and objects in a moving plane as described in this question, are moving at the same speed as the plane even if there is no individual movement of these objects.
However, this question describes a person sitting still in a moving plane. This means that;
- The person is motionless in relation to everything in the plane i.e the person is not moving even if other things in the plane are.
- The person is in motion compared to everything on the ground i.e. the person is moving at the same speed as the plane, hence, in comparison with the ground, the person is moving.
Therefore, options A and B are correct
Answer:
Young's modulus for the rope material is 20.8 MPa.
Explanation:
The Young's modulus is given by:
Where:
F: is the force applied on the wire
L₀: is the initial length of the wire = 3.1 m
A: is the cross-section area of the wire
ΔL: is the change in the length = 0.17 m
The cross-section area of the wire is given by the area of a circle:
Now we need to find the force applied on the wire. Since the wire is lifting an object, the force is equal to the tension of the wire as follows:
Where:
: is the tension of the wire
: is the weigh of the object = mg
m: is the mass of the object = 1700 kg
g: is the acceleration due to gravity = 9.81 m/s²
Hence, the Young's modulus is:
Therefore, Young's modulus for the rope material is 20.8 MPa.
I hope it helps you!
