<span>2. Conduction transfers energy from one particle to another
This is true</span>
Answer:
Option D - 0.2 s
Explanation:
We are given;
Initial velocity; u = 7 m/s
Height of table; h = 1.8m
Now,since we want to find the time the car spent in the air, we will simply use one of Newton's equation of motion.
Thus;
h = ut + ½gt²
Plugging in the relevant values, we have;
1.8 = 7t + ½(9.8)t²
4.9t² + 7t - 1.8 = 0
Using quadratic formula to find the roots of the equation gives us;
t = -1.65 or 0.22
We can't have negative t value, thus we will pick the positive one.
So, t = 0.22 s
This is approximately 0.2 s
The angular frequency in rev/s of the combination when they start rotating together is 1.8 rev/s.
Apply conservation of angular momentum:
Ii.ωi=If.ωf
⇒ 1/2mR² ×3.0=( 1/2mR²+m(2R)²/12)ωf
⇒ωf =1.8rev/s.
A scalar representation of rotation rate in physics is called angular frequency, or "". It speaks of the angular displacement per unit of time, the rate of change of a sinusoidal waveform's phase, or the rate of change of the sine function's argument. The difference between angular frequency (measured in radians per second) and frequency (measured in cycles per second, also known as Hz) is two. Instead of the letter f, the symbol for frequency in this figure is. an axis-centered rotating sphere. Points further from the axis move more quickly, fulfilling = v / r. Angular frequency (), also referred to as radial or circular frequency, calculates the amount of angular momentum per unit of time. Therefore, it is measured in degrees (or radians) per second.
Learn more about angular frequency here:
brainly.com/question/29107224
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The velocity of the girl is -4.8 m/s.
Using the principle of conservation of linear momentum, The total momentum of bodies before and after collision is constant. Since the two objects are stationary, the initial momentum of each body is zero.
Thus;
0 = (80 × 3) + (50 × v)
0 = 240 + 50 v
-240 = 50 v
v = -240/50
v = -4.8 m/s
Note that the negative sign shows that the velocity of the girl is in opposite direction that that of the girl.
Learn more about momentum: brainly.com/question/904448