1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mart [117]
3 years ago
14

Block 1, of mass m1 = 3.90 kg , moves along a frictionless air track with speed v1 = 31.0 m/s . It collides with block 2, of mas

s m2 = 51.0 kg , which was initially at rest. The blocks stick together after the collision.
What is the change ΔK=Kfinal−Kinitial in the two-block system's kinetic energy due to the collision?
Physics
2 answers:
Nostrana [21]3 years ago
7 0
The energy would remain equal to that of the initial kinetic energy since it is a frictionless surface. However if it is an inelastic collision then energy would be lost due to sound and heat.
Setler [38]3 years ago
4 0

Answer:

ΔK= -1741. 09 J

Explanation:

Theory of collisions

Linear momentum is a vector magnitude (same direction and direction as velocity) and its magnitude is calculated like this:

P=m*v

where:

p : Linear momentum

m : mass

v : velocity

There are 3 cases of collisions : elastic, inelastic and plastic.

For the three cases the total linear momentum quantity is conserved:

P₀=Pf  Formula (1)

P₀ :Initial  linear momentum quantity

Pf : Initial  linear momentum quantity

Nomenclature and data

m₁:  block 1  mass = 3.90 kg

V₀₁: initial block 1 speed,  =31.0m/s

Vf₁: final  block 1  speed

m₂:  block 2 mass =  51.0 kg

V₀₂: initial  block 2  speed= 0

Vf₂: final  block 2  speed

Problem development

For this problem the collision is plastic ,then, the blocks stick together after the collision and Vf₁=Vf₂=Vf

We assume that the Block 1 moves to the right before the collision (+) and The joined blocks move to the right after the collision(+).

We apply formula (1)

P₀=Pf

m₁*V₀₁+m₂*V₀₂=m₁*Vf₁+m₂*Vf₂

m₁*V₀₁+m₂*V₀₂=(m₁+m₂) Vf

3.9*31+51*0=(3.9+51) Vf

120.9+0 = 54.9*Vf

Vf = 120.9/54.9

Vf = 2.2 m/s

ΔK in the two-block system's kinetic energy due to the collision

ΔK=Kfinal−Kinitial

ΔK: Change in kinetic energy (J)

Kfinal: final kinetic energy (J)

Kinitial : initial kinetic energy (J)

Kinitial=(1/2 )m₁*V₀₁²+(1/2 )m₂*V₀₂²= (1/2 )(3.9)*(31)²+(1/2 )(51)*0=1873.95 J

Kfinal = (1/2 )(m₁+m₂)*Vf²=  (1/2 )(3.9+51)* (2.2)² = 132.85 J

ΔK= 132.85 J−1873.95 J

ΔK= -1741. 09 J

You might be interested in
What's Inertia ????☁️☁️​
Assoli18 [71]

Explanation:

the inability to change the position from rest to motion or motion to rest by themselves is inertia.

3 0
3 years ago
3. A bicycle has a momentum of 25.00 kg* m/s and a velocity of 2.5 m/s . What is the bicycle's
Anna35 [415]

Answer:

10 kg

Explanation:

The question is most likely asking for the mass of the bicycle.

Momentum is the product of an object's mass and velocity. Mathematically:

p = m * v

Where p = momentum

m = mass

v = velocity

Hence, mass is:

m = p / v

From the question:

p = 25 kgm/s

v = 2.5 m/s

Mass is:

m = 25 / 2.5 = 10 kg

The mass of the bicycle is 10 kg.

In case the question requires the Kinetic energy of the bicycle, it can be gotten by using the formula

K. E = ½ * p * v

K. E. = ½ * 25 * 2.5 = 31.25 J

5 0
3 years ago
A worker pushed a 33 kg block 6.1 m along a level floor at constant speed with a force directed 23° below the horizontal. if the
jenyasd209 [6]
The work done occurs only in the direction the block was moved - horizontally. Work is given by:

W = F(h) * d

Where F(h) is the force applied in that direction (horizontal) and d is the distance in that direction. In this case, F(h) is the horizontal component of the applied force, F(app). However, the question doesn't give us F(app), so we need to find it some other way.

Since the block is moving at a constant speed, we know the horizontal forces must be balanced so that the net force is 0. This means that F(h) must be exactly balanced by the friction force, f. We can express F(h) as a function of F(app):

F(h) = F(app)cos(23)

Friction is a little trickier - since the block is being PUSHED into the ground a bit by the vertical component of the applied force, F(v), the normal force, N, is actually a bit more than mg:

N = mg + F(v) = mg + F(app)sin(23)

Now we can get down to business and solve for F(app) - as mentioned above:

F(h) = f
F(h) = uN
F(h) = u * (mg + F(v))
F(app)cos(23) = 0.20 * (33 * 9.8 + F(app)sin(23))
F(app) = 76.8

Now that we have F(app), we can find the exact value of F(h):

F(h) = F(app)cos(23)
F(h) = 76.8cos(23)
F(h) = 70.7

And now that we have F(h), we can find W:
W = F(h) * d
W = 70.7 * 6.1
W = 431.3

Therefore, the work done by the worker's force is 431.3 J. This also represents the increase in thermal energy of the block-floor system.
3 0
3 years ago
What is required for both the light-dependent and light-independent reactions to proceed?
djyliett [7]
<span>ATP is required for both light-dependent and light-independent reactions.
ATP stands for </span> adenosine triphosphate.
 Hope this helps ;)

3 0
3 years ago
A hockey stick strikes a hockey puck of mass 0.17 kg. If the force exterted on the hockey puck is 35.0 N and there is a force of
GREYUIT [131]

Answer:

a=190\ m/s^2

Explanation:

Mass of a hockey puck, m = 0.17 kg

Force exerted by the hockey puck, F' = 35 N

The force of friction, f = 2.7 N

We need to find the acceleration of the hockey puck.

Net force, F=F'-f

F=35-2.7

F=32.3 N

Now, using second law of motion,

F = ma

a is the acceleration of the hockey puck

a=\dfrac{F}{m}\\\\a=\dfrac{32.3}{0.17}\\\\a=190\ m/s^2

So, the acceleration of the hockey puck is 190\ m/s^2.

5 0
3 years ago
Other questions:
  • Some students want to calculate the work done by friction as an object with unknown mass moves along a straight line on a rough
    9·1 answer
  • How would the force of Earth's gravity change if a satellite were to orbit at a distance that was only 1/2 of its original orbit
    12·1 answer
  • The half life of radium 222 is 38 seconds if you had a 12 gram sample how much would be left after 72 seconds
    9·1 answer
  • If a species can adapt to a changing environment, or ____, its descendants will survive.
    5·1 answer
  • A 0.6 kg ball is initially at rest on a frictionless, horizontal surface. It is struck by a 0.4 kg ball initially moving with a
    7·1 answer
  • What is the maximum speed (in units of m/s) with which a car can round a
    10·1 answer
  • Velocities of two bodies A and B are given in vectors notation as va =i+2j-3k and Vb=3i+2j-k what will be the relative velocity
    12·1 answer
  • PLEASE HELP! WILL MARK BRAINLIEST!
    9·1 answer
  • Match the variables with quantities
    14·1 answer
  • The safest way to view an image of the sun is to use.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!