# Determine the time of impact

1. Nov 16, 2013

### SamAnthony

1. The problem statement, all variables and given/known data
A ball of mass 50g is thrown horizontally against a wall such that it strikes it
at a velocity of 12ms-1. If it exerts a force of 3N on the wall, determine the
time of impact.

2. Relevant equations

3. The attempt at a solution

I drew the diagram and made the direction and wrote the values neatly on my paper as it's sort of a must to do this and it makes me understands the work better. Does the 50g needs to be changed and converted into kg?

2. Nov 16, 2013

### Kishlay

is the collision elastic??

3. Nov 16, 2013

### Kishlay

as we know
dp=F.dt
and hence you could find the answer

4. Nov 16, 2013

### Kishlay

yes it is needed to....!!!!!!

5. Nov 16, 2013

### SamAnthony

I got totally confused! that's the full question. So is it 0.2s?

6. Nov 16, 2013

### Kishlay

i think the question is some how incomplete..... please look and write all the information given in the question......!!!!!!!!!!

7. Nov 16, 2013

### SamAnthony

That's the full question! maybe there's a trick in it? not sure, otherwise there's another value which could be taken as 0?

8. Nov 16, 2013

### Kishlay

then it will be . change in momentum = Δp = p(initial)-p(final)
assume the ball is movin along +ve x direction
then
Δp = p-(-p)= 2p
an hence pu it in the above equation

9. Nov 16, 2013

### Kishlay

click thanks on it.....:)

10. Nov 16, 2013

### SamAnthony

Sure! :) I'm new to this, and I'm figuring this forum out! and thanks for your help too

11. Nov 16, 2013

### Kishlay

he he he ok......!!!!!

12. Nov 16, 2013

### haruspex

you don't need to know. Change in momentum = ∫F.dt.