If a serve hits the net, what happens?

babymother [125]

Newton’s First Law of Motion - if an object is at rest, it takes un-

balanced forces to make it move. Conversely, if an object is moving

it takes an unbalanced force to make it change it’s direction or speed.

Newton was the first to see that such apparently diverse phenomena as a satellite moving near the Earth's surface and the planets orbiting the Sun operate by the same principle: Force equals mass multiplied by acceleration, or F=ma.

7 0

3 years ago

Read 2 more answers

A wheel of diameter 40.0 cm starts from rest and rotates with a constant angular acceleration of 3.00 rad/s^2. At the instant th

xxMikexx [17]

Answer:

ac= 15.07 m/s²

Explanation:

The Wheel rotates with a constant angular acceleration.:

Centripetal acceleration is calculated as follows:

ac =ω² *R Formula (1)

ac =v² / R Formula (2)

Kinematics of the wheel

We apply the equations of circular motion uniformly accelerated :

ωf²= ω₀² + 2αθ Formula (3)

v = ω* R Formula (4)

Where:

θ : angle that the wheel has rotated in a given time interval (rad)

α : angular acceleration (rad/s²)

ω₀ : initial angular speed ( rad/s)

ωf : final angular speed ( rad/s)

v: tangential velocity of a point on the rim ( m/s)

R : radius of wheel (m)

ac: centripetal acceleration, (m/s²)

Data:

D = 40.0 cm : diameter of the wheel

R = D/2= 40.0 cm/ 2 = 20 cm = 0.2m

α = 3.00 rad/s^2

ω₀ = 0

n = 2 revolutions : number of revolutions

θ =2πn (rad) = 2π*2 (rad) = 4π rad

Calculate of the ωf

We replace data in the formula (3)

ωf²= ω₀² + 2αθ

ωf²= 0 + 2(3)(4π)

ωf²= 24π

$w_{f} = \sqrt{24\pi }$

ωf = 8.68 rad/s

Calculate of the v

We replace data in the formula (4)

v = ω*R

v = (8.68)*(0.2)

v = 1.736 m/s

Calculate of the ac

We replace data in the formula (1)

ac = ( ω)²*(R)

ac = (8.68)²*(0.2)

ac = 15.07 m/s²

We replace data in the formula (2)

ac = v²/ R

ac = ( 1.736 )²/(0.2)

ac = 15.07 m/s²

7 0

4 years ago

Flash floods can cause vehicles to float and fill with water, trapping and drowning people. while especially dangerous at night

IceJOKER [234]

I think the answer is: 6 inches

On average, the distance between Car's engine to the ground is around 8-10 inches.. But for small cars, the distance between car's engine to the ground could be as low as 5 inches - 6 inches from the ground.

When the flood reach the car's engine level, the water will got into the engine and disrupt it function, causing the car became unable to work properly

3 0

3 years ago

Match the situation with the energy transformation ITEMBANK: Move to Top A boy shooting a rubber band across the classroom A chi

Sonbull [250]

A boy shooting a rubber band across the classroom -->
Elastic potential energy transformed into kinetic energy
The initial energy is the energy stored in the muscles of the boy's arm, which is elastic potential energy. This is converted into motion of the rubber, therefore kinetic energy

A child going down a slide on a playground --> Gravitational potential energy transformed into kinetic energy
On top of the slide, all the energy of the child is gravitational potential energy due to its height with respect to the ground (E=mgh). when it moves down the slide, this is converted into kinetic energy, because the child acquires a speed v (E=1/2 mv^2)

Rubbing your hands together to warm them on a cold day --> Kinetic energy being transformed into thermal energy 
When rubbing hands, we are moving them (kinetic energy), and this energy raises the temperature of the hand's surface (thermal energy)

Turning on a battery operated light --> 
Chemical potential energy transformed into radiant energy 
A battery works by mean of chemical reactions (chemical potential energy), producing light (so, emitting energy by radiation, i.e. radiant energy)

Using a dc electric motor --> Electrical energy transformed into kinetic energy
A dc electric motor works using currents (so, electrical energy), and the energy produced can be used for example to accelerate a car (kinetic energy)

Using a gas power heater to warm a room --> Chemical potential energy transformed into thermal energy
A gas power heater burns gases (so, chemical reaction, i.e. chemical potential energy) to raise the temperature of the room (thermal energy)

Using a hand crank generator to produce electric current --> Kinetic energy transformed into electrical energy
In a hand-crank generator, the handle is being rotated (kinetic energy) in order to produce an electric current (electrical energy)

Using the light in your room that is plugged into the wall --> Electrical energy transformed into radiant energy
The lamp works by using electrical current flowing into a resistor (electrical energy) and it produces light, so it emits energy by electromagnetic radiation (radiant energy)

3 0

3 years ago

A student hangs a balloon from a string then rubs it on their hair and releases it. They rub a second balloon on their hair then

REY [17]

Answer:

c

Explanation:

tha two ballon have acquired similar charges they therefore repel each other

5 0

3 years ago