Answer:
26i-28j
Explanation:
Mathematically, rate of change of something with respect to another is obtained through the operation called differentiation. Integration is the reverse process of differentiation.
We know that force is the rate of change of momentum.
that is,
F=
where,
P=momentum
t=time
dP=small change in momentum
dt=small change in time
dP=Fdt (multiplying both sides with dt)
To get change of momentum within a particular time interval, we have to integrate the above expression giving the necessary limits according to the problem.
Here, we have to calculate the change in momentum between 1.0s and 2.0s. So, the limit of integration is 1.0 to 2.0.
Thus,
=
where,
p=momentum at t=1s
P=momentum at t=2s
substituting F in the above equation,
=
= P-p = Change in momentum between 1.0s and 2.0s
= (Since we can integrate each term of an expression separately)
=
=26i-28j
therefore the change in momentum between 1.0s and 2.0s is 26i-28j.
Note: the answer we got is a vector. Because momentum is a vector and therefore change in momentum is also a vector
The answer is the second one, because in exothermic reactions energy is released.
Do what on a tape diagram? A picture must be posted.
The formula is
V = final velocity = initial velocity U + ( acceleration a * time duration t )
V = U + a t
= 4.5 m/s + 2.5 m/sec² * 7 sec = 4.5 + 17.5 = 22 m /sec
Acceleration means, every second the velocity or speed increases by that amount. Here it is 2.5. After one second velocity become 2.5 m/s more. after 2 seconds it is 5 m/s more. after 3 seconds, speed is 7.5 m/s more than at start. Like this after 7 seconds, the speed is 7 * 2.5 higher than at the beginning. so computer the total.
A star's brightness also depends on its proximity to us. The more distant an object is, the dimmer it appears. Therefore, if two stars have the same level of brightness, but one is farther away, the closer star will appear brighter than the more distant star - even though they are equally bright!