the figure below shows the graph of force,F (y axis)acting on a trolley of 0.4kg against time,t (x axis)
20---------
........._--
........._...--
........._....---
........._......---
........._.......-----
0........5............9
The velocity of the trolley is constant between t=0ms and t=5ms.
Use the figure above to calculate the impulse acting on the trolley between 0 and 9ms.
THE MARK SCHEME SAYS:
IMPULSE 20 x 5 x 10-3 1/2 x 20 X 4 X 10-3
=0.14 Ns
i DONT UNDERSTAND WHERE THE NUMBERS CAME FROM THE EQUATION USED (AS LEVEL) AND ID LIKE SOMEONE TO STEP BY SEP EXPLAIN THIS TO ME PLEASE
PS: EQUATIONS I KNOW:
p=mv
f X change in t =change in p
if you can use these equations please do it would be helpful
The "10-3" bit especially confuses me as i dont know where those number came from and wat it is for/ wat equation
i figured out that f x change in t =change in p is the equations used and nowi understand that bit so it became:
change in momentum= 20 x 5=100
change in momentum= 1/2(20x4)=40
i just dont get the 10-3 bit
do you have any idea what ms means?
that 4 and 5 in your change in momentum is .004, and .005 , and I bet that has something to do with your 10^-3
no its 10-7 as in it equals to 3 AND you minus it, its not a power. Please post hrelp with this in mind
To calculate the impulse acting on the trolley between 0 and 9 milliseconds, we can use the formula for impulse:
Impulse = Force x Change in Time
From the graph, we can see that the force, F, is constant at 20 Newtons between t = 0 milliseconds and t = 5 milliseconds. The time interval in this case is 5 milliseconds.
So, we have:
Impulse = 20 N x 5 ms
Now, we need to make sure the units are consistent. In this case, we want to convert milliseconds to seconds. There are 1000 milliseconds in 1 second, so we divide 5 ms by 1000 to get it in seconds:
Impulse = 20 N x (5 ms / 1000) s
Simplifying this:
Impulse = 20 N x 0.005 s
Next, let's calculate this value:
Impulse = 0.1 Ns
So, based on the information from the graph, the impulse acting on the trolley between 0 and 9 milliseconds is 0.1 Ns.
Regarding the "10-3" part, it represents the conversion factor from milliseconds to seconds. Since we want to work with consistent units, we divide milliseconds by 1000 to convert them to seconds. This is the reason for including the "10-3" in the equation.