Answer:
The speed of the baseball is approximately 19.855 m/s
Explanation:
From the question, we have;
The frequency of the microwave beam emitted by the speed gun, f = 2.41 × 10¹⁰ Hz
The change in the frequency of the returning wave, Δf = +3190 Hz higher
The Doppler shift for the microwave frequency emitted by the speed gun which is then reflected back to the gun by the moving baseball is given by 2 shifts as follows;
Where;
Δf = The change in frequency observed, known as the beat frequency = 3190 Hz
= The speed of the baseball
c = The speed of light = 3.0 × 10⁸ m/s
f = The frequency of the microwave beam = 2.41 × 10¹⁰ Hz
By plugging in the values, we have;
The speed of the baseball, ≈ 19.855 m/s
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
Answer: the density changed, the salt dissolved in the water, the salt and the water can still be separated into their individual molecules.
Explanation: physical changes are changes in size, shape, or state. Another way to think about a physical change is any change not involving a change in the substance’s chemical identity. You cannot write a chemical equation for salt water because the chemical identity is still salt AND water
trust me i did it
D. it is thickest in the middle
This is an example of inertia - the body keeps it's energy because there is no force applied to it. When we try to stop it's motion, it resists. A man is not rigidly attached to the bus, so he keeps moving forward, at least until he hits the front window from inside. Answer is D.
