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
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You have to do the math of each and see which one adds up to 66.5
Answer:
50 N
Explanation:
Since the refrigerator doesn’t move, that means the force of friction equals the amount of force the child exerts on the fridge. If the friction force were greater than the force by the child, the fridge would start accelerating towards the child. If it were less than the force the child exerted, the fridge would start accelerating away from the child. Therefore, the net force must be 0, in this case, the friction force is equal to the force the child exerted, for it to stay at rest (as Newton’s First Law stated).
I hope this helps! :)
Answer:
Explanation:
a )
Each blade is in the form of rod with axis near one end of the rod
Moment of inertia of one blade
= 1/3 x m l²
where m is mass of the blade
l is length of each blade.
Total moment of moment of 3 blades
= 3 x
x m l²
ml²
2 )
Given
m = 5500 kg
l = 45 m
Putting these values we get
moment of inertia of one blade
= 1/3 x 5500 x 45 x 45
= 37.125 x 10⁵ kg.m²
Moment of inertia of 3 blades
= 3 x 37.125 x 10⁵ kg.m²
= 111 .375 x 10⁵ kg.m²
c )
Angular momentum
= I x ω
I is moment of inertia of turbine
ω is angular velocity
ω = 2π f
f is frequency of rotation of blade
d )
I = 111 .375 x 10⁵ kg.m² ( Calculated )
f = 11 rpm ( revolution per minute )
= 11 / 60 revolution per second
ω = 2π f
= 2π x 11 / 60 rad / s
Angular momentum
= I x ω
111 .375 x 10⁵ kg.m² x 2π x 11 / 60 rad / s
= 128.23 x 10⁵ kgm² s⁻¹ .
Answer:
Explanation:
There are two hypotheses she could test:
A cat's heart rate changes while it is napping.
A cat's heart rate does not change while it is napping.