All categories

2 years ago

A hooligan throws a stone vertically down with an initial speed of 17 m/s from the roof of a building 51 metres above the

Physics

1 answer:

pshichka [43]2 years ago

4 0

Answer:

Explanation:

impact velocity is

√(18² + 2(-9.8)-51) = 36 m/s

average velocity is (17 + 36)/2 = 26.5 m/s

t = d/v = 51 / 26.5 = 1.9 s

if ground is origin and UP positive

0 = 51 - 17t - ½(9.8)t²

quadratic formula

t = (17 ±√(17² - 4(-4.9)(51))) / (2(-4.9))

t = (17 ± 36) / -9.8

t = - 5.4 s which we ignore as the stone is not thrown yet

t = 19 s

You might be interested in

When the distance between two masses is doubled, the gravitational attraction between

mrs_skeptik [129]

The new gravitational attraction will be 1/4 as much

Explanation:

The magnitude of the gravitational force between two objects is given by

$F=G\frac{m_1 m_2}{r^2}$

where

$G=6.67\cdot 10^{-11} m^3 kg^{-1}s^{-2}$ is the gravitational constant

m1, m2 are the masses of the two objects

r is the separation between them

In this problem, the original force between the two objects is F, when they are separated by a distance r.

Later, the distance between the two objects is doubled, so the new distance is

$r'=2r$

Therefore, the new force will be

$F'=G\frac{m_1 m_2}{(2r)^2}=\frac{1}{4}(\frac{Gm_1 m_2}{r^2})=\frac{F}{4}$

Therefore, the new force will be one-fourth as much.

Learn more about gravitational force:

brainly.com/question/1724648

brainly.com/question/12785992

#LearnwithBrainly

5 0

2 years ago

What is the relationship between an object’s mass and its gravitational potential energy?.

antiseptic1488 [7]

Answer:

If we’re talking about objects on the Earth, the gravitational potential energy is given by:

Explanation:

PEg=mgh

so the energy is proportional to the mass ( m ), but also to the strength of the gravitational field ( g ), and the height ( h ) to which the mass is lifted.

5 0

1 year ago

Which of the following have the same density. number 26

marusya05 [52]

1 cubic cm is the same as 1 mL, so the answer would be C.

8 0

2 years ago

An automobile traveling 95 km/h overtakes a 1.30-km-long train traveling in the same direction on a track parallel to the road.

SOVA2 [1]

Answer:

Same direction: t=234s; d=6.175Km

Opposite direction: t=27.53s; d=0.73Km

Explanation:

If the automobile and the train are traveling in the same direction, then the automobile speed relative to the train will be $v_{AT}=v_A-v_T$ (the train must see the car advancing at a lower speed), where $v_A$ is the speed of the automobile and $v_T$ the speed of the train.

So we have $v_{AT}=(95km/h)-(75Km/h)=20Km/h$ .

So the train (anyone in fact) will watch the automobile trying to cover the lenght of the train L at that relative speed. The time required to do this will be:

$t = \frac{L}{v_{AT}} = \frac{1.3Km}{20Km/h} = 0.065h=234s$

And in that time the car would have traveled (relative to the ground):

$d=v_At=(95Km/h)(0.065h)=6.175Km$

If they are traveling in opposite directions, we have to do all the same but using $v_{AT}=v_A+v_T$ (the train must see the car advancing at a faster speed), so repeating the process: