What do radio waves and microwaves have in common?

Which answer choice?? I have trouble with this physics concept :/

Zepler [3.9K]

Answer:

Your weight

Explanation:

8 0

3 years ago

Calculate the power of the elevator if it can raise 290 kg of mass 30 flights of stairs (300 m) in 17 seconds

Advocard [28]

Answer:

Power = 50204 [watts]

Explanation:

We know that the power is defined by the following expression:

Power = Work/time

where:

Power [watts]

time [seconds]

The work done will be the following:

Work = Force * distance [Joules]

Force[Newtons]

distance[meters]

Force = mass* gravity

Force=290 [kg]*9.81[m/s^2] =2844.9[N]

Work = 2844.9[N]*300[m] = 853470[J]

Therefore

Power = 853470 / 17 = 50204 [watts]

5 0

3 years ago

You are riding in the passenger seat of a car as it goes around a tight turn. You slide across the seat to the passenger side do

DochEvi [55]

Answer:

1. b. The door is exerting a centripetal force on you that balances the centrifugal force of the turn.

2. b. There is no net force acting on the object.

Explanation:

1. This is because as you move to the right due to the centrifugal force of the turn, a corresponding centripetal force acts on you due to the door which does not allow you fall out of the car since, the door is exerting a centripetal force on you that balances the centrifugal force of the turn.

So, the answer is b

2. This is because, since the object moves at a constant speed and thus does not accelerate, no net force can act on it since, a net force would imply that the object accelerates. Note that a constant speed does not imply that no force acts on it. It only shows that the resultant or net force is zero since the object does not accelerate.

So, there is no net force acting on the object.

So, b is the answer.

6 0

2 years ago

A 0.6 kg block attached to a spring of force constant 13.6 N/m oscillates with an amplitude of 9 cm. Find the maximum speed of t

mash [69]

Answer:

1) 0.43 meters per second

2) 0.21 meters per second

3) 1.02 $\frac{m}{s^{2}}$

4) 0.66 seconds

Explanation:

part 1

By conservation of energy, the maximum kinetic energy (K) of the block is at equilibrium point where the potential energy is zero. So, at the equilibrium kinetic energy is equal to maximum potential energy (U):

$K=U$

$\frac{mv^2}{2}=\frac{kx_{max}^2}{2}$

With m the mass, v the speed, k the spring constant and xmax the maximum position respect equilibrium position. Solving for v

$v=\sqrt{\frac{kx_{max}^2}{m}}=\sqrt{\frac{(13.6)(0.09m)^2}{0.6}}=0.43\frac{m}{s}$

part 2

Again by conservation of energy we have kinetic energy equal potential energy:

$\frac{mv^2}{2}=\frac{kx_{max}^2}{2}=$

$v=\sqrt{\frac{kx_{max}^2}{m}}=\sqrt{\frac{(13.6)(0.045m)^2}{0.6}}=0.21\frac{m}{s}$

part 3

Acceleration can be find using Newton's second law:

$F=ma$

with F the force, m the mass and a the acceleration, but elastic force is -kx, so:

$-kx=ma$

$a= -\frac{kx}{m}=-\frac{(13.6)(0.045)}{0.6}=-1.02\frac{m}{s^{2}}$

part 4

The period of an oscillator is the time it takes going from one extreme to the other one, that is going form 4.5 cm to -4.5 cm respect the equilibrium position. That period is:

$T=2\pi\sqrt{\frac{m}{k}}=T=2\pi\sqrt{\frac{0.6}{13.6}}=1.32s$