How many full length strands of hair are collected from the scalp to use as a sample?

gravity is a force between any two objects with mass. why doesn't a person feel a gravitational force between him/herself and an

antiseptic1488 [7]

Answer:

c)the gravitational forces of people is so small it is overshadowed by that of earth.

Explanation:

The gravitational force between two objects is given by:

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

where

G is the gravitational constant

m1 and m2 are the masses of the two objects

r is the distance between the two objects

From the formula, we see that the gravitational force depends on the masses of the objects: since the mass of the Earth ( $5.97\cdot 10^{24} kg$ is much much larger than the average mass of one person (80-100 kg), then the gravitational force exerted by the Earth on a person is also much much larger than the gravitational force between two people.

4 0

3 years ago

Read 2 more answers

Suppose a moving car has 2000 J of kinetic energy. If the carʹs speed doubles, how much kinetic energy would it then have?

Bond [772]

Answer:

option A

Explanation:

given,

Kinetic energy of the car = 2000 J

speed of the car is doubled

we know,

$KE_1 = \dfrac{1}{2}mv^2$

$2000= \dfrac{1}{2}mv^2$ ........(1)

now, speed of the car is doubled

v' = 2 v

$KE_2 = \dfrac{1}{2}mv'^2$

$KE_2 = \dfrac{1}{2}m(2v)^2$

from equation (1)

$KE_2 = 4\times \dfrac{1}{2}m(v)^2$

$KE_2 = 4\times 2000$

$KE_2 = 8000\ J$

Hence, the Kinetic energy would be equal to 8000 J.

The correct answer is option A.

8 0

2 years ago

A passenger train travels 392 mi in the same time that it takes a freight train to travel 322 mi. If the passenger train travels

Yuri [45]

Answer:

Explanation:

Given

distance traveled by Passenger train is $d_1=392\ mi$

distance traveled by Freight train is $d_2=322\ mi$

Both take same time to travel

suppose speed of freight train is x mph

so speed of passenger train is 20+x mph

we know time $=\frac{distance}{speed}$

$t=\frac{392}{20+x}=\frac{322}{x}$

$392x=322x+322\times 20$

$70x=322\times 20$

$x=92\ mph$

speed of passenger train $x+20=112\ mph$

6 0

3 years ago

An athelete runs some distance before taking a long jump because : give answer

insens350 [35]

Hi Pupil Here's your answer ::

➡➡➡➡➡➡➡➡➡➡➡➡➡

An Athelete run some distance before taking a long jump because by running the Athelete gives himself larger inertia of motion.

⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅

Hope this helps .....

3 0

3 years ago

Diagram shows the velocity time graph for a particle moving in 16 seconds.

Leya [2.2K]

Answer:

The detailed calculations are shown below;

Explanation:

a)The maximum acceleration of the particle:

It is seen that the maximum change in velocity is at the time between 8s to 10s.

Maximum acceleration: $\frac{V}{t}$