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3 years ago

How to calculate kinetic energy of a projectile at the highest point of a projectile?

2 answers:

6 0

Kinetic energy is half the product of the mass and the square velocity and at highest point the velocity is 0 thus the kinetic energy is 0 J

DIA [1.3K]3 years ago

3 0

For a projectile the total energy is equal to the kinetic energy that is 1/2 mv and the the potential energy mgh that add. Initially the total energy is all kinetic energy at the highest point the energy is all potential.so kinetic energy at that point is 0.
hope it helps

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Which of the following is not a way to make exercising on a cold day safer?

IRISSAK [1]

Answer:

Explanation:

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3 years ago

Read 2 more answers

Can someone help??

Paul [167]

Answer:

F = 2520 N

Explanation:

We have,

The maximum acceleration of a fist in a karate punch is 4200 m/s². The mass of the fist is 0.6 kg.

It is required to find the force that the wood place on the fist. Force is given by the product of mass and its acceleration such that,

F = ma

$F=0.6\times 4200\\\\F=2520\ N$

So, the force of 2520 N is acting on the wood.

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3 years ago

Recall from Chapter 1 that a watt is a unit of en- ergy per unit time, and one watt (W) is equal to one joule per second ( J·s–1

harkovskaia [24]

Answer:

Explanation:

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We also know that frequency and wavelength are related by $f=\frac{c}{\lambda}$ , so we have $E_N=\frac{N h c}{\lambda}$ , where c is the <em>speed of light</em>.

We will want the number of photons, so we can write

$N=\frac{\lambda E_N}{h c}$

We need to know then how much energy do we have to calculate N. The equation of power is $P=E/t$ , so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be $E_N$ .

Putting this paragraph in equations:

$E_N=(\frac{4}{100})E=0.04Pt=(0.04)(100W)(1s)=4J$ .

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$N=\frac{\lambda E_N}{h c}=\frac{(520 \times10^{-9}m) (4J)}{(6.626\times10^{-34}Js) (299792458m/s)}=1.047 \times10^{19}$

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3 years ago

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liubo4ka [24]

Answer:

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2 years ago

A crane exerts a net force of 900 N upward on a 750-kilogram car as the crane starts to lift the car from the deck of a cargo sh

melisa1 [442]

Answer: 1.2m/s^2

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3 years ago