When a runner increases her speed from 75 m/s to 115 m/s in 25 s,her acceleration is ____

A ball is thrown upward at an angle with a speed and direction such that it reaches a maximum height of 16.0 m above the point i

shtirl [24]

To solve this problem it is necessary to apply the concepts related to the kinematic equations of motion for which the height of a particle is defined as a function of gravity as,

$v^2 = 2gh$

Where,

h = Height

g = Gravity constant

v = Velocity

There is not change in the horizontal component, therefore there is only the component horizontal given (18m/s) and the vertical component:

$v^2=2*g*h$

$v^2=2*9.8*16$

$v=17.70 m/s$

Applying the vector theory to find the magnitude of a vector we have to

$|\vec{V}| = \sqrt{17.7^2+18^2}$

$|\vec{V}| = 25.38m/s$

The speed at which the ball was thrown was 25.38

3 0

3 years ago

Which of the following statements are true?

Tems11 [23]

Answer:

1) A time-varying magnetic field will produce an electric field.

4) A time-varying electric field will produce a magnetic field.

Explanation:

1) A time-varying magnetic field will produce an electric field.

TRUE

time varying magnetic field will produce electric field which is given as

$E = \frac{r}{2}\frac{dB}{dt}$

2) Time-varying electric and magnetic fields can propagate through space only if there is no matter in their path.

FALSE

Time varying electric field and magnetic field will induce each other and it can travel through any medium as well as it can travel without any medium also

3) Electric and magnetic fields can be treated independently only if they vary in time.

FALSE

electric field can be due to stationary charge and magnetic field due to current carrying elements so it is not compulsory to have time varying

4) A time-varying electric field will produce a magnetic field.

TRUE

Time varying electric field will produce magnetic field given as

$B = \frac{\mu_o\epsilon_o A}{2r}\frac{dE}{dt}$

3 0

3 years ago

The sun generates both mechanical and electromagnetic waves. Which statement about those waves is true?

Vladimir [108]

Answer: The correct answer for this question is letter (B) The electromagnetic waves reach Earth, while the mechanical waves do not. The sun generates both mechanical and electromagnetic waves. Space, between the sun and the earth is a nearly vacuum. So mechanical wave can not spread out in the vacuum.

Hope this helps!

4 0

3 years ago

Prove that the period of a simple pendulum T=2×22/7×rootl/g

Rudik [331]

Answer:

Explanation:

Check the attachment.

By the definition of the simple harmonic motion,

The motion of a particle whose acceleration is

1. Always directed towards the center of the motion.

2. Proportional to the distance from center of the motion.

We get, a ∝ -x

where

a = acceleration

x = distance of the particle from center of the motion

- sign says acceleration is in opposite direction of motion

Check the other attachment for proof of a = -ω²x (or a = -ω²y)

x and y are both use to denote distance from center of the motion

Download pdf

4 0

3 years ago

If matter cannot be created nor destroyed the how was matter created

Assoli18 [71]

It can’t be created nor destroyed although it can be changed from one form to the other

I hope this helps

Have a happy holidays:)

7 0

3 years ago

When a runner increases her speed from 75 m/s to 115 m/s in 25 s,her acceleration is _____