Acceleration of gravity is proportional to 1/D² .
('D' is the distance from the Earth's center.)

We need (D / R)² = 9.8
('R' is the Earth's radius.)

D/R = √9.8 = 3.13

Distance from Earth's center = 3.13 R
Distance above Earth's surface = 2.13 R = about 13,570 km =====================================================

Accelerarea de gravitate este proporțională cu 1 / D².
('D este distanța de centrul Pământului.)

Avem nevoie de (D / R) ² = 9,8
('R' este raza Pământului.)

D / R = √9.8 = 3,13

Distanța de la centrul Pamantului = 3,13 R
Distanța de deasupra suprafetei Pamantului = 2.13 R = aproximativ 13,570 km

6 0

4 years ago

Serena drops a 5-kg book down the stairwell. What is the book's final velocity vf after it falls

elena55 [62]

Answer:

39.2m/s

Explanation:

Given parameters:

Mass of book = 5kg

Time taken for fall = 4s

Unknown:

Final velocity of the book = ?

Solution:

Serena dropped the book from rest therefore, the initial velocity of the book is 0.

Let us find the appropriate motion equation to solve this problem;

V = U + gt

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity = 9.8m/s²

t is the time taken

Insert the given parameters and solve;

V = 0 + 9.8 x 4 = 39.2m/s

3 0

3 years ago

Suppose that we replace the aluminum with a mystery metal and repeat the experiment in the video. As in the video, the mass of t

dimaraw [331]

Answer:

b) one-third as great.

Explanation:

As we know that same heat is supplied in this experiment

so we will have

$Q = ms\Delta T$

now we know that both are initially at same temperature

then their final temperatures are

$T_1 = 40 degree$

$T_2 = 80 degree$

now we have

$m_1s_1 (40 - 20) = m_2s_2(80 - 20)$

so we have

$m_2s_2 = \frac{20}{60} m_1s_1$

so heat capacity of mystery metal is 1/3 times that of water

6 0

3 years ago

Read 2 more answers