A 200-N woman is standing on a concrete floor. How much force does the floor exert on her?

.A box falls to the ground from a delivery truck traveling at 30 m/s. After hitting the road, it slides 45 m to

Romashka-Z-Leto [24]

Answer:

t = 3 seconds

Explanation:

Given that,

Initial speed, u = 30 m/s

Final speed, v = 0

It slides 45 m to rest.it take the box to come to rest

We need to find how long it take the box to come to rest.

Let a be the acceleration and t is time.

$v^2-u^2=2ad\\\\a=\dfrac{v^2-u^2}{2d}\\\\a=\dfrac{(30)^2-u^2}{2(45)}\\\\=10\ m/s^2$

Now finding time.

$t=\dfrac{v-u}{a}\\\\t=\dfrac{30-0}{10}\\\\t=3\ s$

So, the required time is 3 seconds.

8 0

3 years ago

billiardballsnew2 A white billiard ball with mass mw = 1.49 kg is moving directly to the right with a speed of v = 3.09 m/s and

Kobotan [32]

Answer:

Final velocity of white ball is 0m/s

Final velocity of black ball is 3.09m/s

Explanation:

An elastic collision is one that conserves internal kinetic energy

An internal kinetic energy is the sum of kinetic energies of objects in the system

Initial kinetic energy of white ball is Vi1 = 3.09m/s

Final kinetic energy of white ball is Vf1 = ?

Initial kinetic energy of black ball is Vi2 = 0m/s

Final kinetic energy of black ball is Vf2 = ?

m1 = 1.49kg mass of white ball

m2 = 1.49kg mass of black ball

The formula to calculate internal kinetic energy is

1/2m1Vf1^2 + 1/2m2Vf2^2 = 1/2m1Vi1^2

Solving the equation

1.Vf1 = (m1 - m2)Vi1/m1+m2

Vf1 = (1.49-1.49)*3.09/1.49+1/49

Vf1 = 0m/s

2. Vf2 = 2m1Vi1/m1+m2

Vf2 = 2*1.49*3.09/1.49+1.49

Vf2 = 3.09m/s

N:B following the general principle of collision when 2 bodies of same masses collide in elastic collision they exchange velocities.

7 0

3 years ago

A body of mass 120 g is taken vertically upwards to reach the height of 5m,claculate work done

Anuta_ua [19.1K]

FOLLOW ME FOR CLEARING YOUR NEXT DOUBT

3 0

3 years ago

A sled travels 15 meters down a slope inclined at 30 degrees with a horizontal. What is the horizontal displacement of the sled?

Arte-miy333 [17]

Length of the slope is given as

$L = 15 m$

also the inclination is given as

$\theta = 30 degree$

now the horizontal displacement is let say "x"

now from geometry we can say

$\frac{x}{L} = cos30$

$x = L cos30$

now substitute all values in it

$x = 15 * cos30$

$x = 12.99 m$

<em>so it will displace horizontally by 12.99 m</em>

6 0

3 years ago

A spool of thread, free to unwind, is on a horizontal surface (with friction) and pulled directly upward (+y) at all times. The

k0ka [10]

Answer:

The Correct Answer is "D"

Explanation:

For Detail of this answer Please see the attached file.

6 0

3 years ago