Ask question

Ask question

All categories

3 years ago

7

It takes 6s for a stone to fall from the top of a building to the ground calculate i.the height of the building ii.the speed of

the stone just before it strikes the ground (g=10ms^-2

1 answer:

omeli [17]3 years ago

5 0

Answer:

fffffff

Explanation:

You might be interested in

An electrical heater is used to supply 245.0 J of energy to a 15.0 g sample of aluminum, originally at 310.0 K. Determine the fi

Softa [21]

Answer:

$T_f=328.1 K$

Explanation:

To determine the final temperature of the sample, we use the specific heat formular as follows:

$Q=mCp(T_f-T_0)\\T_f=\frac{Q}{mCp} +T_{0}\\mol Al= \frac{15g}{26.98gmol^{-1}}=0.555 mol\\T_f=\frac{245.0J}{0.555mol\times24.35Jmol^{-1}K^{-1}} +310.0K\\T_f=328.1 K$

Finally, the temperature of the aluminium sample has raised 18 K.

8 0

3 years ago

If you're ever standing on a mountaintop when a dark cloud passes overhead and your hair stands up, get off the mountain fast. H

OleMash [197]

Answer:

The hairs would have acquired charge by the passing of dry winds resulting in the loss of electron.

Explanation:

While standing on the top of a mountain if a person gets its hairs stand up after a cloud passes over, this might happen due to the static electric charges on the lower surface of the cloud are opposite in nature to that of hairs which the hairs would have acquired by the passing of dry winds which would have resulted in the loss of electron from the hair tip.

Similar case happens when we rub a dry plastic ruler or a dry plastic comb on our hairs.

8 0

4 years ago

A person walks 45 m East and then walks 39 m at an angle 40◦ North of East. What is the magnitude of the total displacement? Ans

vredina [299]

Answer:

r = 78.95 m

Explanation:

given,

Person Walk in east, r₁ = 45 m

Then he walk, r₂= 39 m in the direction of 40◦ North of East.

writing the total displacement in x- direction

r₁ₓ = 45 m

r₂ₓ = 39 cos 40°

r₂ₓ = 29.87 m

total displacement in x-direction

rₓ = r₁ₓ + r₂ₓ

rₓ = 45 + 29.87

rₓ = 74.87 m

displacement in y-direction

r_{1y} = 0 m

r_{2y} = 39 sin 40°

r_{2y} = 25.07 m

total displacement in y- direction

r_y = 25.07 m

using Pythagoras theorem for the magnitude calculation

$r = \sqrt{r_x^2 + r_y^2}$

$r = \sqrt{74.87^2 +25.07^2}$

r = 78.95 m

The magnitude of total displacement is equal to 78.95 m.

8 0

3 years ago

What kind of image is formed by a plane mirror

Tom [10]

<span>The image formed by a plane mirror is always virtual (meaning that the light rays do not actually come from the image), upright, and of the same shape and size as the object it is reflecting. A virtual image is a copy of an object formed at the location from which the light rays appear to come.</span>

3 0

4 years ago

The normal force equals the magnitude of the gravitational force as a roller coaster car crosses the top of a 58-m-diameter loop

dedylja [7]

Answer:

16.87 m/s

Explanation:

To find the speed of the car at the top, when the normal force is equal the gravitational force, we just need to equate both forces:

$N = P$

$m*a_c = mg$

$a_c$ is the centripetal acceleration in the loop:

$a_c = v^2/r$

So we have that:

$mv^2/r = mg$

$v^2/r = g$

$v^2 = gr$

$v = \sqrt{gr}$

So, using the gravity = 9.81 m/s^2 and the radius = 29 meters, we have:

$v = \sqrt{9.81 * 29}$

$v = \sqrt{284.49} = 16.87\ m/s$

The speed of the car is 16.87 m/s at the top.

5 0

3 years ago