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3 years ago

Which action is not an example of work?

Physics

1 answer:

Korvikt [17]3 years ago

8 0

Answer:

option 3

Explanation:

work is said to be the ability to move an object from it initial position. therefore, holding a tray is not a work

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When a ray of light passes at an angle to the normal from one material into another material in which its speed is higher?

Gnesinka [82]

I think your talking about refraction and if so the first medium it existed in before entering the second usually has the higher speed especially it the first medium is less denser than the second

4 0

4 years ago

(NEED HELP PLEASE) A physics student goes to the roof of the school, 24.15 m above the ground, and drops a pumpkin straight down

slavikrds [6]

Answer:

t = 2.2 s

Explanation:

Given that,

Height of the roof, h = 24.15 m

The initial velocity of the pumpkin, u = 0

We need to find the time taken for the pumpkin to hit the ground. Let the time be t. Using second equation of kinematics to find it as follows :

$h=ut+\dfrac{1}{2}at^2$

Here, u = 0 and a = g

$h=\dfrac{1}{2}gt^2\\\\t=\sqrt{\dfrac{2h}{g}} \\\\t=\sqrt{\dfrac{2\times 24.15}{9.8}} \\\\t=2.22\ s$

So, it will take 2.22 s for the pumpkin to hit the ground.

7 0

3 years ago

Looking at group 2 on the periodic table which of these elements probably has the lowest ionic radius

lakkis [162]

I think the answer is Helium.

Please tell me if I'm wrong.

7 0

3 years ago

What is the difference in mass between the smaller nuclei that fuse together and the newly formed heavier nucleus called?

baherus [9]

Answer:

ESTA!!!

Explanation:

3 0

3 years ago

In the design of a supermarket, there are to be several ramps connecting different parts of the store. Customers will have to pu

tatuchka [14]

Answer:

3.90 degrees

Explanation:

Let g= 9.81 m/s2. The gravity of the 30kg grocery cart is

W = mg = 30*9.81 = 294.3 N

This gravity is split into 2 components on the ramp, 1 parallel and the other perpendicular to the ramp.

We can calculate the parallel one since it's the one that affects the force required to push up

F = WsinΘ

Since customer would not complain if the force is no more than 20N

F = 20

$294.3sin\theta = 20$

$sin\theta = 20/294.3 = 0.068$

$\theta = sin^{-1}0.068 = 0.068 rad = 0.068*180/\pi \approx 3.90^0$

So the ramp cannot be larger than 3.9 degrees

6 0

4 years ago