The resistance of a conductor is given by
where L is the length of the wire,
the resistivity of the material and A the cross-sectional area.
We can see that if all the other quantities do not change, if the new length of the conductor is 4 times the original length:
, then the new resistance is also 4 times the original value:
Boyle's law says that the volume of a gas varies inversely with the pressure. When the volume of a certain gas is 4l , the pressure is 720 kpa (kilopascals). What is the pressure when the volume is 10l ?
The kinetic energy in the first case is 4 times more than the second case.
Hence, option D)It is 4 times greater is the correct answer.
<h3>What is Kinetic Energy?</h3>
Kinetic energy is simply a form of energy a particle or object possesses due to its motion.
It is expressed as;
K = (1/2)mv²
Where m is mass of the object and v is its velocity.
Given that;
- For the first case, velocity v = 16m/s
- For the second case, velocity = 8m/s
- Let the mass of the car be m
For the first case, kinetic energy of the car will be;
K = (1/2)mv²
K = (1/2) × m × (16m/s)²
K = (1/2) × m × 256m²/s²
K = mass × 128m²/s²
For the second case, kinetic energy of the car will be;
K = (1/2)mv²
K = (1/2) × m × (8m/s)²
K = (1/2) × m × 64m²/s²
K = mass × 32m²/s²
Comparing the kinetic energy of the car with the same mass but different velocity, we can see that the kinetic energy in the first case is 4 times more than the second case.
Hence, option D)It is 4 times greater is the correct answer.
Learn more about kinetic energy here: brainly.com/question/12669551
#SPJ1
Answer:
Magnitude of displacement = 2.07 km
Magnitude of average velocity = 1.17 kmph
Explanation:
Let east represent positive x axis and north represent positive y axis.
A bird watcher meanders through the woods, walking 1.93 km due east, 1.03 km due south, and 3.84 km in a direction 52.8 ° north of west.
1.93 km due wast
s ₁ = 1.93 i km
1.03 km due south
s₂ = -1.03 j km
3.84 km in a direction 52.8 ° north of west
s₃ = -3.84 cos 52.8 i + 3.84 sin 52.8 j = -2.32 i + 3.06 j km
Total displacement
s = s ₁+ s₂+ s₃ = 1.93 i - 1.03 j -2.32 i + 3.06 j = -0.39 i + 2.03 j
Magnitude of displacement, 
Time taken = 1.771 hour
Magnitude of average velocity, 
We Know,
K.E. = 1/2 mv²
480 = 1/2 (m)(8)²
m = 960/64
m = 15 Kg
So, the mass of the object is 15 Kg
