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3 years ago

When you lift a book of the ground to your desk, what kind of work do you do, negative or positive?

1 answer:

8 0

It would be kinetic energy. Let's say the book is weighs 10 Newtons you need to use a force of 10 Newtons to lift the book. In other words it's positive. As you move the book you're giving it energy. Namely potential energy which will turn to kinetic energy if you let it go. So you're changing it's position and energy.

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A huge rotating cloud of particles in space gravitate together to form an increasingly dense ball. As ir shrinks in size, the cl

Trava [24]

Answer:

rotates faster

Explanation:

A huge rotating cloud of particles in space gravitate together to form an increasingly dense ball As it shrinks in size, the cloud rotates faster. Because Angular momentum is conserved, so when it shrinks the moment of inertia decreases, then angular speed must increase. So it rotates fast.

4 0

3 years ago

What do you think happens to the temperature when water changes to gas?

Olenka [21]

Answer:

it gets hot and more hot until it turns to gas

Explanation:

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3 years ago

Why are chloroplasts essentially to the process of photosynthesis to occurs

lesya [120]

they absorb sunlight and turn it into glucose I think.

8 0

3 years ago

Read 2 more answers

A charge of q= +15 uC moves in a Northeast direction with a speed 5 m/s, 25 degrees East of a magnetic field, pointing North, wi

grin007 [14]

Explanation:

It is given that,

Magnitude of charge, $q=15\ \mu C=15\times 10^{-6}\ C$

It moves in northeast direction with a speed of 5 m/s, 25 degrees East of a magnetic field.

Magnetic field, $B=0.08\ j$

Velocity, $v=(5\ cos25)i+(5\ sin25)j$

$v=[(4.53)i+(2.11)j]\ m/s$

We need to find the magnitude of force on the charge. Magnetic force is given by :

$F=q(v\times B)$

$F=15\times 10^{-6}[(4.53i+2.11j)\times 0.08\ j]$

Since, $i\times j=k\ and\ j\times j=0$

$F=15\times 10^{-6}[(4.53i)\times (0.08)\ j]$

$F=0.00000543\ kN$

$F=5.43\times 10^{-6}\ kN$

So, the force acting on the charge is $5.43\times 10^{-6}\ kN$ and is moving in positive z axis. Hence, this is the required solution.

6 0

3 years ago

What is the importance of star ranting labelilling of an electrical appliance?

Misha Larkins [42]

Answer:

The standard of efficiency varies by product category

these are called BEE star label and they show how much electricity the appliance consumes in year each appliance gets btw one and five stars with five stars meaning that it's extremely efficienct andis likely to keep your electricity bills in check

 hope it's helpful

5 0

3 years ago