How do you make the chemical equations LiOH+H2(SO4) and H2O+Li2(SO4) balanced?

a person throws a rock at 3 M/s down over the edge of a very tall cliff on Earth how far will the Rock at fall in 4 seconds if t

ValentinkaMS [17]

Answer:

The rock will fall 90.4m downwards

Explanation:

Here, the acceleration is constant and it is equal to acceleration due to gravity. Therefore the question depicts a situation of uniformly accelerated motion in a straight line. So, let us refresh the three equations of uniformly accelerated straight line motion.

v = u + at

$s = ut + \frac{1}{2}at^{2}$

$v^{2} = u^{2} +2as$

where,

u = initial velocity

v = final velocity

s = displacement

a = acceleration

t = time

Since we are dealing with vectors (velocity, acceleration and displacement), we have to take their directions in to account. So we must adopt a coordinate system according to our convenience. Here, we are taking point of throwing as origin, vertically upward direction as positive y axis and vertically downward direction as negative y axis.

Thus,

u = -3m/s (since it is along negative y axis)

a = g = -9.8m/ $s^{2}$ (since it is along negative y axis)

t = 4s

s = ?

The only equation that connects all these quantities is

$s = ut + \frac{1}{2}at^{2}$

Substituting the values in the equation gives,

$s = (-3)x4 + \frac{1}{2}(-9.8)4^{2}$

s = -12 - 78.4

s = -90.4m

Thus the rock will fall 90.4m downwards. The negative sign indicates that the displacement is along negative y axis which is downwards.

5 0

3 years ago

What units do physicists use to measure heat energy and electrical energy?

vagabundo [1.1K]

<span>Physicists use certain units to measure heat energy and electrical energy:

- Joule (Watt sec )
- Watt - hour
- Kilowatt- hour
- Calorie

Hope this helps!

</span>

6 0

3 years ago

A ball is dropped from a building of height h. Derive an equation for its velocity just before it hits the ground. Assume no air

swat32

Answer:

The final velocity of the ball just hits the ground is $\sqrt{2gh}$ .

Explanation:

A ball is dropped from the height h. As the ball is dropped means there is no initial velocity given to the ball.

GIVEN:

The distance traveled by the ball is equal to h.

Initial velocity of the ball is zero.

Concept:

Two type of force comes into play in dropping of ball.

1. Gravitational force

Due to gravitational force ball forced to fall downward towards the surface.

2. Air resistance

Air develops drag force on the ball in opposite direction of the gravitational force.

Assumption:

There is no air resistance in falling of ball. So, there will be no drag force on the ball.

Calculation:

It is given that a ball is dropped from a building of height h.

The Newton’s equations of motion are as follows:

$V^{2}-u^{2}=2as$

$s=ut+\frac{1}{2}at^{2}$

$v=u+at$

STEP 1

Newton’s equation of motion is expressed as follows:

$V^{2}-u^{2}=2as$

Here, V is final velocity of the ball just before the ball hits the ground, a is acceleration due to gravity, u is the initial velocity of the ball and s is the distance traveled by the ball.

Here, initial velocity is zero. So, u = 0 m/s.

Vertical distance traveled by the ball is h. So, s= h.

Only gravitational force is responsible for motion as well as for acceleration. Thus, the acceleration due to gravity acts on the ball. Acceleration due to gravity is denoted by small g.

Acceleration due to gravity is constant for different planate. The acceleration due to gravity for the earth is 9.8 m/s². Here, no planet is defined. So the acceleration due to gravity is a = g.

Substitute 0 for m/s, g for a and h for s in above equation as follows:

$V^{2}-u^{2}=2as$

$V^{2}-(0)^{2}=2gh$

$V^{2}=2gh$

$v=\sqrt{2gh}$

Thus, the final velocity of the ball just hits the ground is $\sqrt{2gh}$ .

5 0

4 years ago

When a loaded cannon is fired, which physical variables are affected?

GREYUIT [131]

Answer:

it can explode lol

Explanation:

4 0

3 years ago

Help This is Urgent

MaRussiya [10]

I don’t use the metric system, so I used feet and then went back.

25 meters is about 82 feet.
So around 82 feet per minute (kinda slow LOL)

82 (feet per minute) x 90 (minutes) = 7380 feet (in 90 minutes)

7380 feet is equal to 2249.424 meters.

(I hope that helped)

6 0

3 years ago

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