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4 years ago

If a Girl Bounces a Ball, At what point does the ball have velocity?

Physics

1 answer:

mihalych1998 [28]4 years ago

5 0

An object ALWAYS has velocity, although the velocity may be zero for most of the time, or even all the time.

'Velocity' means the object's speed AND the direction in which it's moving.

As long as the girl stands and holds the ball in her hand, the ball's velocity is zero. As soon as she drops it out of her hand, it starts having velocity that's not zero.

While it's bouncing, its velocity is . . .

== growing and downward while it's falling from her hand toward the ground,

== zero for the instant of time when it hits the ground and changes direction from down to up,

== shrinking and upward while it's rising from the ground to her hand,

== zero for the instant of time when it hits her hand and changes direction from up to down.

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Please help! No links or spam, I will report.

Anettt [7]

Answer:

It is convenient to divide the photosynthetic process in plants into four stages, each occurring in a defined area of the chloroplast: (1) absorption of light, (2) electron transport leading to the reduction of NADP+ to NADPH, (3) generation of ATP, and (4) conversion of CO2 into carbohydrates (carbon fixation).

Explanation:

5 0

3 years ago

Read 2 more answers

In a lightning bolt, a large amount of charge flows during a time of 1.2 x 10-3 s. Assume that the bolt can be represented as a

ohaa [14]

Answer: 10.58 C has flowed during the lightning bolt

Explanation:

Given that;

Time of flow t = 1.2 × 10⁻³

perpendicular distance r = 21 m

Magnetic field B = 8.4 x 10⁻⁵ T

Now lets consider the expression for magnetic field;

B = u₀I / 2πr

the current flow is;

I = ( B × 2πr ) / u₀

so we substitute

I = ( (8.4 x 10⁻⁵) × 2 × 3.14 × 21 ) / 4π ×10⁻⁷

= 0.01107792 / 0.000001256

= 8820 A

Hence the charge flows during lightning bolt will be;

q = It

so we substitute

q = 8820 × 1.2 × 10⁻³

q = 10.58 C

therefore 10.58 C has flowed during the lightning bolt

6 0

4 years ago

Calculate the efficiency of a hair dryer which takes in 4500J of energy per second and transfers 150J as useful heat energy.

Basile [38]

Answer:

η = 0.0333 = 3.33 %

Explanation:

The efficiency of any device is defined as the ratio of the useful output obtained from that device to the input required by the device. Therefore, the general formula to find the efficiency of any device is given as follows:

$\eta = \frac{O}{I}$

where,

η = efficiency of hair dryer = ?

O = Useful Output Given by the Hair Dryer = 150 J

I = Input Energy Required by the Hair Dryer = 4500 J

Therefore,

$\eta = \frac{150\ J}{4500\ J}\\$

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3 years ago

What does N.W.A means?

MissTica

Answer: Well N.W.A is a hip hop group that started back in the late 1900s back then they where pretty cool and fun to listen too well there music was about how life was when they where young well thats all i can say unless you talking about something different.

Explanation:

3 0

4 years ago

A boy on board a cruise ship drops a 30. 0 gm marble into the ocean. If the resistive force proportionality constant is 0. 500 k

mixer [17]

The terminal speed of the marble is 0.588 m/s.

Given:

We know that,

F = mg ......(1)

where,

F = force

m = mass

g = acceleration due to gravity

Also,

v = F/k ......(2)

where,

v = terminal speed

k = proportionality constant

Substituting the value of F from equation (1) in equation (2)

v = mg/k .......(3)

Given,

m = 30 g = 0.030 kg

k = 0.500 kg/s

g = 9.8 m/s²

To find,

v =?

Put the values in equation (3)

v = mg/k

v = 0.03(9.8)/ 0.500

= 0.294/0.500

= 0.588 m/s

Learn more about the calculation of force, refer to:

brainly.com/question/15562875

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8 0

2 years ago