Recall that if the colliding objects have hard surfaces , the collision is elastic

Efficiency of a machine is always less than 100% why?

kifflom [539]

The reason the efficiency is always less than 100% is because there is always some sort of friction in the machine.

Answer: because of friction

7 0

2 years ago

The gas state of water

salantis [7]

Answer:

The gas state of water is water vapour. It is formed by boiling liquid water or from the sublimation of ice (sublimation is the process of converting a solid to a liquid). Hope this helps!

4 0

3 years ago

Read 2 more answers

A batter hits a foul ball. The 0.14-kg baseball that was approaching him at 40 m/s leaves the bat at 30 m/s in a direction perpe

swat32

Answer:

<em>7 kgm/s or 7 Ns</em>

Explanation:

Since the velocity are perpendicular to each other, the impulses will also be perpendicular.

From newton's second law of motion,

Impulse = mass×velocity

I = mv............. Equation 1

For the horizontal,

I₁ = mv₁......... Equation 2

Given: m = 0.14 kg, v₁ = 40 m/s

Substitute into equation 2

I₁ = 40(0.14)

I₁ = 5.6 kgm/s

Also for the vertical,

I₂ = mv₂.............. Equation 3

Given: m= 0.14 kg, v₂ = 30 m/s

Substitute into equation 3

I₂ = 0.14(30)

I₂ = 4.2 kgm/s

Using Pythagoras to get the resultant impulse

I = √(I₁²+I₂²)................ Equation 4

Substitute the value of I₁ and I₂ into equation 4

I = √(5.6²+4.2²)

I = √(31.36+17.64)

I = √49

<em>I = 7 kgm/s or 7 Ns</em>

5 0

4 years ago

Read 2 more answers

A freshly prepared sample of radioactive isotope has an activity of 10 mCi. After 4 hours, its activity is 8 mCi. Find: (a) the

Maurinko [17]

Answer:

(a). The decay constant is $1.55\times10^{-5}\ s^{-1}$

The half life is 11.3 hr.

(b). The value of N₀ is $2.38\times10^{11}\ nuclei$

(c). The sample's activity is 1.87 mCi.

Explanation:

Given that,

Activity $R_{0}=10\ mCi$

Time $t_{1}=4\ hours$

Activity R= 8 mCi

(a). We need to calculate the decay constant

Using formula of activity

$R=R_{0}e^{-\lambda t}$

$\lambda=\dfrac{1}{t}ln(\dfrac{R_{0}}{R})$

Put the value into the formula

$\lambda=\dfrac{1}{4\times3600}ln(\dfrac{10}{8})$

$\lambda=0.0000154\ s^{-1}$

$\lambda=1.55\times10^{-5}\ s^{-1}$

We need to calculate the half life

Using formula of half life

$T_{\dfrac{1}{2}}=\dfrac{ln(2)}{\lambda}$

Put the value into the formula

$T_{\dfrac{1}{2}}=\dfrac{ln(2)}{1.55\times10^{-5}}$

$T_{\dfrac{1}{2}}=44.719\times10^{3}\ s$

$T_{\dfrac{1}{2}}=11.3\ hr$

(b). We need to calculate the value of N₀

Using formula of $N_{0}$

$N_{0}=\dfrac{3.70\times10^{6}}{\lambda}$

Put the value into the formula

$N_{0}=\dfrac{3.70\times10^{6}}{1.55\times10^{-5}}$

$N_{0}=2.38\times10^{11}\ nuclei$

(c). We need to calculate the sample's activity

Using formula of activity

$R=R_{0}e^{-\lambda\times t}$

Put the value intyo the formula

$R=10e^{-(1.55\times10^{-5}\times30\times3600)}$

$R=1.87\ mCi$

Hence, (a). The decay constant is $1.55\times10^{-5}\ s^{-1}$

The half life is 11.3 hr.

(b). The value of N₀ is $2.38\times10^{11}\ nuclei$

(c). The sample's activity is 1.87 mCi.

4 0

4 years ago

Some snakes have special sense organs that allow them to see the heat emitted from warm blooded animals what kind of an electrom

Artyom0805 [142]

The heat emitted from anything is carried in the form of infrared waves. (C)

7 0

3 years ago