20. A cannon shoots a ball at 38 m/s at an angle of 30°. Ignore the original height of the cannon and assume level ground.

A kicker kicks a ball off the ground at 29.5 mi/hr and at 42.5 degrees.

deff fn [24]

Answer:

20.3m

Explanation:

the formula used was

s=(u^2sin^2∆)÷2g

4 0

3 years ago

How do you do this problem?

kvasek [131]

Explanation:

First, find the velocity of the projectile needed to reach a height h when fired straight up.

Given:

Δy = h

v = 0

a = -g

Find: v₀

v² = v₀² + 2aΔy

(0)² = v₀² + 2(-g)(h)

v₀ = √(2gh)

Now find the height reached if the projectile is launched at a 45° angle.

Given:

v₀ = √(2gh) sin 45° = √(2gh) / √2 = √(gh)

v = 0

a = -g

Find: Δy

v² = v₀² + 2aΔy

(0)² = √(gh)² + 2(-g)Δy

2gΔy = gh

Δy = h/2

5 0

3 years ago

Explain how electricity is generated and distributed, and why it is so useful and powerful for modern society.

yarga [219]

Answer:

Generation ----transmission---distribution

Explanation:

Electricity is generated from the generating station which could be (thermal, hydro, nuclear, coal etc) ,it is generated at a low voltage and is being step up to a higher voltage with the aid of transformers. This transformers step up and step down voltages from one level to another. At the transmission end they ensure the voltage get to the distribution end .the distribution end ensures the voltages are being supplied to nearby homes. The rated voltage for homes is 230v in some countries or 110V in other countries.

Electricity is useful and powerful for modern society because majority of the equipments in use today depends on electricity for use.which makes it very important.

3 0

3 years ago

Read 2 more answers

A marble rolling at a speed of 2.71 m/s falls of the end of a table that is 1.25 m high. How far from the base of the table does

katrin [286]

Answer:

The marble lands at a distance of 1.36 m from the base of the table.

Explanation:

The motion of the marble falling off the table is a projectile with initial velocity in the horizontal direction only.

The motion can be solved in two directions, the horizontal and vertical direction.

Along the vertical direction, the initial velocity is 0 m/s as it has only horizontal component initially. Also acceleration in the vertical direction is acceleration due to gravity.

Let us use equation of motion in vertical direction.

$y-y_0=v_{0y}t+\frac{1}{2}at^2$

Where,

$v_{0y}\rightarrow \textrm{vertical component of the initial velocity}.\\y\rightarrow \textrm{final position of the marble}\\y_0\rightarrow \textrm{initial vertical position}\\a_y\rightarrow \textrm{acceleration in the vertical direction}\\t\rightarrow \textrm{time taken to reach bottom}$

Now, plug in 0 for $y$ , $1.25$ for $y_0$ , 0 for $v_{0y}$ , -9.8 for $a_y$ . This gives,

$0-1.25=0+\frac{1}{2}(-9.8)t^2\\-1.25=-4.9t^2\\t^2=\frac{-1.25}{-4.9}\\t^2=0.255\\t=\sqrt{0.255}=0.501\ s$

Therefore, time to reach bottom is 0.501 s.

Now, consider the horizontal motion. There is no acceleration in the horizontal direction. So, distance is given as the product of horizontal velocity and time taken.

Horizontal distance covered by the marble is given as:

$x=v_{0x}\times t=2.71\times 0.501=1.36 \textrm{ m}$

Therefore, the marble lands at a distance of 1.36 m from the base of the table.

6 0

3 years ago

What two quantities are always conserved in a nuclear reaction equation?

kupik [55]

Answer:B

Explanation:

Option A:

In the nuclear reactions,neutron can be split into proton an electron.

In this case,the number of protons are increasing,increasing the atomic number.

Hence,the atomic number is not conserved.

Option B:

In any reaction the sum of number of neutrons and number of protons remain constant before and after the reaction.

Option C:

The mass number may change for the atoms.For example $\alpha$ emission reduces the atomic number by $2.$

Option D:

In the nuclear reactions,neutron can be split into proton an electron.

So,they number of neutrons may change.

7 0

3 years ago