More than 5 million collisions occur every ___________
A. Day
B. Month
C. Year


Answer 1

c im pretty sure its year. Sorry if im wrong.

Related Questions


If two such generic humans each carried 2.5 coulomb of excess charge, one positive and one negative, how far apart would they have to be for the electric attraction between them to equal their 600 weight? *An average human weighs about 600 r= .............. km



They would be apart


Electric force between two charged objects is:


With q1, q2 the charges of the humans, r the distance between them and k the constant , so if we want the electric force between them will be equal to their 600 N weight, we should make W=Fe=600 N on (1):

solving for r:


What would be the magnification of a specimen viewed with a compound light microscope that has an objective power of 40x and an ocular lens power of 10x? A.) 40x
B.) 50x
C.) 400x
D.) 500x




The power of a compound microscope is found by combining the power of the lences involved. 
The power of objective lens is 40x and that of ocular lens is 10x. 
So, the power of the microscope is (40x × 10x) = 400x.  

The magnification of a specimen viewed with a compound light microscope that has an objective power of 40x and an ocular lens power of 10x is 400x. The correct answer between all the choices given is the third choice or letter C. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.


A 20 kg wood ball hangs from a 2.0-mlong wire. The maximum tension the wire can withstand without breaking is 400 N. A 1.0 kg projectile traveling horizontally hits and embeds itself in the wood ball. 1. What is the greatest speed this projectile can have without causing the wire to break?

2. What is the greatest speed the wood ball can have after the collision without breaking?



1) the greatest speed the projectile can have without causing the wire to break is v₂ = 94.836 m/s

2) the greatest speed the wood ball can have after the collision without breaking is v= 4.516 m/s


Since the wood ball generates an circular motion when is hit by the projectile, then from Newton's second law:

F = m*a , where a= radial acceleration = v²/R (circular motion) , F= force , m= mass

since F=T - m*g cos θ

T - m*g cos θ = m*v²/R

where T= tension of the wire , R= radius of the circle= wire's length , θ= angle with respect to the vertical axis

In the moment that the projectile hits the wood block, the force is

T₀ - m*g = m*v₀²/R  (θ=0)

then by energy conservation:

kinetic energy  at the bottom + potencial energy  at the bottom= kinetic energy at height h + potencial energy at height h

1/2*m*v₀² = 1/2*m*v² + m*g*R(1- cos θ)

v₀²/R = v²/R + 2*g(1- cos θ)

v²/R = v₀²/R - 2*g(1- cos θ)


T - m*g cos θ = m*v²/R = m*v₀²/R -2*m*g + 2*m*g*cos θ

since T₀ - m*g = m*v₀²/R

T - m*g cos θ = T₀ - m*g -2*m*g + 2*m*g*cos θ


T = T₀ -3*m*g + 3*m*g*cos θ = T₀ -3*m*g*(1- cos θ)

T = T₀ -3*m*g*(1 - cos θ)

since T increases with increasing cos θ , the maximum tension is for cos θ=1 (θ=0)


T max =  T₀  

T₀ - m*g = m*v₀²/R

v max = v₀ = √[(T₀/m - g)*R]= √[(400 N/20kg - 9.8 m/s²)*2 m]= 4.516 m/s

then if the projectile embeds itself in the wood ball, we can assume an inelastic collision . Then by conservation of momentum

m₁*v₁ + m₂*v₂ = (m₁+m₂)*v₀

where 1 represents the wood ball , and 2 the projectile

since 1 is at rest initially, v₁=0. Therefore

m₂*v₂ = (m₁+m₂)*v₀

v₂ = (m₁+m₂)/m₂ *v₀

replacing values

v₂ = (m₁+m₂)/m₂ *v₀ = (20 kg+1 kg)/1 kg * 4.516 m/s = 94.836 m/s


A 0.500 kg mass is oscillating on a spring with k=330 N/m.The total energy of its oscillation is 3.24 J. What is speed of the mass when it is 0.100 m from the EP? (Unit=m/s)


The speed is 2.5 m/s


The total (mechanical) energy of the mass-spring system at any point during the motion is the sum of the kinetic energy (KE) and the potential energy (PE):

and it is constant.

The kinetic energy can be written as


m = 0.500 kg is the mass

v is the speed

While the potential energy is


k = 330 N/m is the spring constant

x is the elongation

So the first equation becomes

Therefore, if we substitute

x = 0.100 m

We can find the speed when the elongation is x = 0.100 m:

Learn more about kinetic and potential energy:


Correct Answer:

2.5 m/s


A mass on a spring oscillates with a period T. Part A If both the mass and the force constant of the spring are doubled, the new period will be If both the mass and the force constant of the spring are doubled, the new period will be a. 4T. b. 2√T. c. T. d. T2√. e. T4.



The new time period will be T.


The time period in terms of spring constant and mass is given by :

If mass and force constant is doubled, m' = 2m and k' = 2k

New time period is given by :

So, the new period will remains the same. Hence, the correct option is (C).


A stone is thrown upward and reaches a maximum height of 45.0 m above its launch point what was the speed with which the stone was thrown


V(f) ^2 = v(I)^2 + 2adeltay
0^2 = v(I)^2 + 2(-9.8)(45)
V(I) = 30 m/s

What is the rms speed of nitrogen molecules contained in a 8.5 m3 volume at 3.5 atm if the total amount of nitrogen is 1900 mol ?



Explanation: Using ideal gas equation:

PV = nRT

P= pressure = 3.5 atm

V= volume =

n = no of moles = 1900

R= gas constant =0.0821 Latm\molK

R= gas constant = 8.314 J/Kmol

T= temperature = 190.7 K

M= molecular mass of nitrogen = 28 g/mol


There is an electromagnetic wave traveling in the -z direction in a standard right-handed coordinate system. What is the direction of the electric field, E→ , if the magnetic field, B→ , is pointed in the +x direction?


Answer: The direction of the electric field, E→, is pointed in the +y direction.


One can use the right hand rule to illustrate the direction of travel of an electromagnetic and thereby get the directions of the electric field, magnetic field and direction of travel of the wave.

The right hand rule states that the direction of the thumb indicate the direction of travel of the electromagnetic wave (in this case the -z direction) and the curling of the fingers point in the direction of the magnetic field  B→ (in this case the +x direction), therefore, the electric field direction E→ is in the direction of the fingers which would be pointed towards the +y direction.


Confused on how to find the mass of player 2. Two hockey players are traveling at velocities of v1 = 13 m/s and v2 = -17 m/s when they undergo a head-on collision. After the collision, they grab each other and slide away together with a velocity of -3.5 m/s. Hockey player 1 has a mass of 122 kg. What is the mass of the other player?

thank you.


here in this type of collision we can use momentum conservation

here we know that

now by above equation of momentum conservation

so mass of the player 2 will be approx 149 kg

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