All categories

3 years ago

What physics principle is used in radar guns to find the speeds of tennis balls and baseballs at sporting events?

Physics

1 answer:

Luda [366]3 years ago

6 0

<h2>Answer: Doppler effect </h2>

Explanation:

A radar gun (also known as a Doppler radar) uses the Doppler effect when measuring "return echoes" after having sent a microwave signal (a type of electromagnetic radiation).

In this context the Doppler effect consists of the change in a wave perceived frequency when the emitter of the waves, and the observer move relative to each other.

In the case of radars, a microwave signal is sent to a target (the tennis or baseball in this case) and then is reflected after "hitting" the target, so that the radar system measures this difference between the sent signal and the reflected signal.

You might be interested in

A 5.45-g combustible sample is burned in a calorimeter. the heat generated changes the temperature of 555 g of water from 20.5°c

Y_Kistochka [10]

Given:
m = 555 g, the mass of water in the calorimeter
ΔT = 39.5 - 20.5 = 19 °C, temperature change
c = 4.18 J/(°C-g), specific heat of water

Assume that all generated heat goes into heating the water.
Then the energy released is
Q = mcΔT
= (555 g)*(4.18 J/(°C-g)*(19 °C)
= 44,078.1 J
= 44,100 J (approximately)

Answer: 44,100 J

3 0

3 years ago

What do radio waves and microwaves have in common?

Tamiku [17]

Answer:

I Will say the Answer is A

Explanation:

5 0

2 years ago

Read 2 more answers

3. A bicycle has a momentum of 25.00 kg* m/s and a velocity of 2.5 m/s . What is the bicycle's

Anna35 [415]

Answer:

10 kg

Explanation:

The question is most likely asking for the mass of the bicycle.

Momentum is the product of an object's mass and velocity. Mathematically:

p = m * v

Where p = momentum

m = mass

v = velocity

Hence, mass is:

m = p / v

From the question:

p = 25 kgm/s

v = 2.5 m/s

Mass is:

m = 25 / 2.5 = 10 kg

The mass of the bicycle is 10 kg.

In case the question requires the Kinetic energy of the bicycle, it can be gotten by using the formula

K. E = ½ * p * v

K. E. = ½ * 25 * 2.5 = 31.25 J

5 0

3 years ago

Two point charges of equal magnitude q are held a distance d apart. Consider only points on the line passing through both charge

NemiM [27]

let us consider that the two charges are of opposite nature .hence they will constitute a dipole .the separation distance is given as d and magnitude of each charges is q.

the mathematical formula for potential is $V=\frac{1}{4\pi\epsilon} \frac{q}{d}$

for positive charges the potential is positive and is negative for negative charges.

the formula for electric field is given as- $E=\frac{1}{4\pi\epsilon} \frac{q}{r^2}$

for positive charges,the line filed is away from it and for negative charges the filed is towards it.

we know that on equitorial line the potential is zero.hence all the points situated on the line passing through centre of the dipole and perpendicular to the dipole length is zero.

here the net electric field due to the dipole can not be zero between the two charges,but we can find the points situated on the axial line but outside of charges where the electric field is zero.

now let the two charges of same nature.let these are positively charged.

here we can not find a point between two charges and on the line joining two charges where the potential is zero.

but at the mid point of the line joining two charges the filed is zero.

5 0

3 years ago

Find the length of a pendulum that oscillates with a frequency of 0.16 hz. the acceleration due to gravity is 9.81 m/s 2 . answe

Vsevolod [243]

The period of the pendulum is the reciprocal of the frequency:
$T= \frac{1}{f}= \frac{1}{0.16 Hz}=6.25 s$

The period of the pendulum is given by
$T=2 \pi \frac{L}{g}$
where L is the length of the pendulum, and g the acceleration of gravity. By re-arranging the formula and using the value of T we found before, we can calculate the length of the pendulum L:
$L=g \frac{T^2}{(2 \pi)^2}=(9.81 m/s^2) \frac{(6.25 s)^2}{(2 \pi)^2}=9.71 m$

7 0

3 years ago