A machine that transforms electrical energy into mechanical energy to produce motion.

A softball player moving 3.89 m/s

Ahat [919]

Answer:

0.119 s

Explanation:

Given that

$U=3.89\ m/s\\a=-1.44\ m/s^2\\S=4.8\ m$

Lets take final speed of the softball after covering 4.8 m = V

We know that

$V^2=U^2+2aS\\V^2=3.89^2-2\times 1.44\times 4.8\\V=3.7\ m/s$

Also We know that

$V=U+at\\$

Putting the value of V ,U and a in the previous equation We get

$3.7=3.89-1.44\times t\\t=0.119\ s$

Therefore slide time will be 0.119 s

3 0

3 years ago

An investigator collects a sample of a radioactive isotope with an activity of 490,000 Bq.48 hours later, the activity is 110,00

Daniel [21]

Answer:

The correct answer is "22.27 hours".

Explanation:

Given that:

Radioactive isotope activity,

= 490,000 Bq

Activity,

= 110,000 Bq

Time,

= 48 hours

As we know,

⇒ $A = A_0 e^{- \lambda t}$

or,

⇒ $\frac{A}{A_0}=e^{-\lambda t}$

By taking "ln", we get

⇒ $ln \frac{A}{A_0}=- \lambda t$

By substituting the values, we get

⇒ $-ln \frac{110000}{490000} = -48 \lambda$

⇒ $-1.4939=-48 \lambda$

$\lambda = 0.031122$

As,

⇒ $\lambda = \frac{ln_2}{\frac{T}{2} }$

then,

⇒ $\frac{ln_2}{T_ \frac{1}{2} } =0.031122$

⇒ $T_\frac{1}{2}=\frac{ln_2}{0.031122}$

$=22.27 \ hours$

3 0

3 years ago

Which statement best describes the situation? Which statement best describes the situation? The car has the greater change of mo

Pachacha [2.7K]

Complete Question

A truck going 15 km/h has a head-on collision with a small car going 30 km/h. Which statement best describes the situation?

A. the truck has the greater change of momentum because it has the greater mass

B. the car has the greater change of momentum because it has the greater speed

C. neither the car nor the truck changes its momentum in the collision because momentum is conserved

D. they both have the same change in magnitude of momentum because momentum is conserved

E. none of the above is necessarily true

Answer:

D. They both have the same change in magnitude of momentum because momentum is conserved

Explanation:

In order to get a good understanding of the solution above we define some

concetps

Momentum

This is defines quantified motion and can be mathematically represented as

Momentum = Mass of the body × Velocity of the body

According to the Law of conservation of momentum states that when two particles collide together in a system that is being isolated that their total momentum before and after their collision is equal this means that the momentum lost by the truck would be the same as the momentum gained by the small car

4 0

3 years ago

According to Newton's third law of motion, which of the following best describes the forces of the tennis racket and the ball?

Effectus [21]

Answer:

OA is the answer

Newton's third law of force states that: for every action (force) in nature there is an equal and opposite reaction. what this means is that if I push on you, you're also pushing me because I have slowed down but now you are falling to the mud.

if you have ever seen newtons balls then you will know what I am talking about, one is moving then it hits the other and it stops moving because now the other one is moving,

I hope this makes sense, if it doesent then go to the net and watch some videos on Newtons third law

hope it helped

8 0

3 years ago

Which ray diagram correctly illustrates what happens when light is incident from the air onto a flat glass surface? The dotted l

prohojiy [21]

Answer:

When light incident at angle more than critical angle then whole beam of light will get reflected at same angle into the same medium

So correct answer is

Option D

Explanation:

Critical angle is the maximum angle of incidence for which light shows the phenomenon of refraction of light

Here light bends at 90 degree angle when light incident at critical angle

Now if the incident light is more than the critical angle then light will follow the rules of reflection and all light rays will get reflected at same angle as that of angle of incidence

So here we can say that correct answer is

Option D

3 0

3 years ago