• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

Messages
373
Reaction score
125
Points
53
Can someone explain the answers to these questions?
The answers are q12)A
EDIT- q9 can be ignored as I found the answer.
 

Attachments

  • Untitled.png
    Untitled.png
    36.7 KB · Views: 21
  • Untitled2.png
    Untitled2.png
    29.1 KB · Views: 11
Messages
6,232
Reaction score
5,003
Points
573
Can someone explain the answers to these questions?
The answers are q12)A
EDIT- q9 can be ignored as I found the answer.

Let the mass of these "things :p" be m.

You must use the principle of linear momentum here, i.e, Sum Of Linear Momentum Before = Sum Of Linear Momentum After

Sum Of Linear Momentum Before = Sum Of Linear Momentum After

(m x 60) + (m x -30) = (2m x v)

30 m = 2 mv

v = 15 m/s

Note: I used -30 since the velocity is in the opposite direction. As for the 2m, it's quite obvious. Since they stick together on impact, thier total mass is m + m = 2m

Hope It Helps.
 
Messages
373
Reaction score
125
Points
53
Let the mass of these "things :p" be m.

You must use the principle of linear momentum here, i.e, Sum Of Linear Momentum Before = Sum Of Linear Momentum After

Sum Of Linear Momentum Before = Sum Of Linear Momentum After

(m x 60) + (m x -30) = (2m x v)

30 m = 2 mv

v = 15 m/s

Note: I used -30 since the velocity is in the opposite direction. As for the 2m, it's quite obvious. Since they stick together on impact, thier total mass is m + m = 2m

Hope It Helps.
Thanks, I used the kinetic energy method. I somehow got that wrong hahha. Can we use that method?
 
Messages
76
Reaction score
17
Points
18
i have a question that why we say latent heat of fusion....why not fission....coz we going from solid to liquid...
though both the words should not be used here since nothing actually happens as such..i think...
any solutions friends...?
 
Messages
76
Reaction score
17
Points
18
what happens to potential energy of fluid when some of its molecules evaporate??
i think it should increase coz intermolecular forces become stronger since no of molecules are now decreased??
or we just say that pe is dependent on no of molecules so in this case issue of pe is invalid...?
 
Messages
76
Reaction score
17
Points
18
can someone explain momentum to me?:)
momentum=product of mass and velocity.
law of conservation of momentum:
total initial momentum equals total final momentum in a isolated system in which bodies interact provided no external force is applied.
m1u1 +m2u2 = m1v1 + m2v2
this law is utilized in solving problems relating to collisions of objects...
types of collisions:
(Perfectly) elastic collision: Both momentum & kinetic energy of the system are conserved.
Inelastic collision: Only momentum is conserved, total kinetic energy is not conserved.
Perfectly inelastic collision: Only momentum is conserved, and the particles stick together after collision. (i.e. move with the same velocity.)
 
Messages
23
Reaction score
4
Points
13
Can Someone xplain how to solve this question??
9702/01/M/J/09 Q20
Answer : D
 

Attachments

  • Untitled.png
    Untitled.png
    18.9 KB · Views: 25
Messages
460
Reaction score
293
Points
73
This is an Edexcel question that I'm having trouble with. I'll write my answer and can someone please point out what's wrong with it (4 marks):
Newton's first law states than an object would continue with constant velocity or remain stationary if there;s no resultant force. When the train decelerates, there is a resultant force acting on each person in the direction that the train is travelling in. THis means that person A would fall and collide with person B as persons B and C would remain in their seats due to the fact that they have their backs on chairs which would absorb the force. Person A's motion is an example of a resultant force quoted in Newton's first law.

I'm pretty sure there's something wrong in there because not each point matches the mark scheme but that is how I would answer it, so does anyone know how they would go about correcting this?
 

Attachments

  • Screen Shot 2013-01-03 at 4.44.50 PM.png
    Screen Shot 2013-01-03 at 4.44.50 PM.png
    64 KB · Views: 15
Messages
6
Reaction score
1
Points
1
A car travels one complete lap around a circular track at a constant speed of 120 km/hr. Determine the magnitude of the displacement of the car in a time of 1.0 minute. (The circumference of a circle is 2πR where R is the radius of the circle.)
 
Top