Pls help!! science.

What will be the average velocity of a body falling in free fall on Earth for 3 s?

SpyIntel [72]

Answer:

29.4m/s

Explanation:

Given parameters:

Time = 3s

Unknown:

Average velocity = ?

Solution:

To solve this problem, we use the expression below:

v = u + gt

v is the average velocity

u is the initial velocity = 0m/s

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

t is the time

So;

v = 0 + (9.8 x 3) = 29.4m/s

6 0

3 years ago

Why is the answer B?

djyliett [7]

Answer:

Explanation:

The center of mass lies on a line that joins position 4 of one start with position 4 of the other star. The shortest distance between these two points will produce the largest velocity. You are using F = m v^2/R

Small R = large force.

Large Force = increased speed.

The masses don't have any effect on the outcome: they remain constant.

7 0

4 years ago

To pull an old stump out of the ground, you and a friend tie two ropes to the stump. You pull on it with a force of 500 N to the

zhannawk [14.2K]

Answer:

C. less than 950 N.

Explanation:

Given that

Force in north direction F₁ = 500 N

Force in the northwest F₂ = 450 N

Lets take resultant force R

The angle between force = θ

θ = 45°

The resultant force R

$R=\sqrt{F_1^2+F_2^2+2F_1F_2cos\theta}$

$R=\sqrt{500^2+450^2+2\times 450\times 500\times cos\theta}$

R= 877.89 N

Therefore resultant force is less than 950 N.

C. less than 950 N

Note- When these two force will act in the same direction then the resultant force will be 950 N.

8 0

3 years ago

In the diagram below, a heavy box is being lifted. What is the function of the pulley in this situation?

zepelin [54]

I believe the correct answer from the choices listed above is option B. The function of the pulley in this situation is to change the direction of the input force. <span> The </span>pulley<span> simply turns a force in one direction into a force in another direction. Hope this answers the question. Have a nice day.</span>

8 0

3 years ago

Read 2 more answers

At Hoover Dam, the distance the water effectively falls before encountering the electric generators depends on the water levels

pashok25 [27]

Answer:

Explanation:

recall that power is energy carried out or work done per time

P=W/t

P=2*10^6*35

t=6*60=420S

W=Energy

E=2*10^6*35*360S

E=25200000000

Energy stored by water from rest is called potential energy. Since the water is falling from a height , we calculate potential energy as thus

E=M*g*h

Assume that the water intakes are effectively 175 m above the electric generators. How much water must pass through the generators to power 2 million 35-W Las Vegas light bulbs for 6.0 minutes?

M=mass of water

g=acceleration due to gravity 9.81m/s^2

h=height ,175m

25200000000=M*9.81*175

M= $\frac{25200000000}{175*9.81}$

M=1716.75kg

3 0

3 years ago

Pls help!! science. ​

Pls help!! science.