Lified True or False

If we increase the speed of rotation of wheel then the sound produced by cardboard touching the spokes of the wheel will become

Anarel [89]

it will become shrill

5 0

3 years ago

A boxer punches a sheet of paper in mid air, and brings it from rest up to a speed of 25 m/s in 0.05 s. if the mass of the paper

zepelin [54]

Ok, so you've got to figure out a force F and you have the speed in which the boxer punches on determinate time and the mass of the sheet of paper.

So based on the formula that says that the Force is equal to the mass multiplied by the acceleration => F=ma.
You look at it and see that you only have mass which is measured on KG so there is no problem.
then you have the acceleration which is measured on meters and is defined by: a = Δv/Δt
So now you can replace the velocity and the time you have there
⇒ a 25m/s / 0.05s
you have computing that ⇒ 50m because the seconds were cancelled out.
and then you plug the meters into the force equation.
F=(0.005kg)(50)
F=0.25N
so the boxer will have a force of 0.25 Newton's.

6 0

3 years ago

Read 2 more answers

You are looking down on a N = 9 turn coil in a magnetic field B = 0.5 T which points directly down into the screen. If the diame

Novay_Z [31]

Answer:

The magnitude of the voltage is $2.27\times10^{-4}\ V$ and the direction of the current is clockwise.

Explanation:

Given that,

Number of turns = 9

Magnetic field = 0.5 T

Diameter = 3 cm

Time t = 0.14 s

We need to calculate the flux

Using formula of flux

$\phi=NAB$

Put the value into the formula

$\phi=9\times\pi\times(1.5\times10^{-2})^2\times0.5$

$\phi=0.003180$

We need to calculate the emf

Using formula of emf

$\epsilon=-\dfrac{d\phi}{dt}$

$\epsilon=-\dfrac{0.003180}{0.14}$

$\epsilon =-0.000227\ V$

$\epsilon=-2.27\times10^{-4}\ V$

Negative sign shows the direction of current.

Hence, The magnitude of the voltage is $2.27\times10^{-4}\ V$ and the direction of the current is clockwise.

8 0

3 years ago

Why is the cycle of cellular respiration and photosynthesis important to life for plants

devlian [24]

The cycle of cellular respiration and photosynthesis are important for the life of plants because cellular respiration uses one of the products of photosynthesis (oxygen), and uses it as one of the reactants along with glucose to produce carbon dioxide. These two cycles help maintain a balance for our atmosphere, even though pollution and other factors have disrupted this balance. Hope this helps! :)

5 0

3 years ago

A car travels in a straight line covering a total distance of 90.0 miles in 60.0 minutes. Which one of the following statements

andrezito [222]

Answer:

E) The average velocity of the car is 90.0 miles per hour in the direction of motion.

Explanation:

Given;

distance covered by the car, d = 90 miles

time taken, t = 60 minutes = 1 hour

The average velocity of the car is given by change in displacement per change in time;

V = Δd / Δt

$V = \frac{x_f - x_o}{t_f -t_o} = \frac{90-0}{1-0} \\\\V = 90 \ miles/hour$

Therefore, the average velocity of the car is 90.0 miles per hour in the direction of motion.

7 0

3 years ago