Answer:
Whenever you see the delta symbol infront of another, it always represents change. In other words:
Δu = u_f - u_i
- u_i means "initial velocity"
- u_f means "final velocity"
And in general, ΔX means Xfinal - Xinitial
Answer:
Speed, u = 29.4 m/s
Explanation:
Given that, A ball thrown straight up climbs for 3.0 sec before falling, t = 3 s
Let u is speed with which the ball is thrown up. When the ball falls, v = 0
Using first equation of motion as :
v = u + at
Here, a = -g
So, u = g × t

u = 29.4 m/s
So, the speed with which the ball was thrown is 29.4 m/s. Hence, this is the required solution.
Answer: 10.3m/s
Explanation:
In theory and for a constant velocity the physics expression states that:
Eq(1): distance = velocity times time <=> d = v*t for v=constant.
If we solve Eq (1) for the velocity (v) we obtain:
Eq(2): velocity = distance divided by time <=> v = d/t
Substituting the known values for t=15s and d=155m we get:
v = 155 / 15 <=> v = 10.3
In radio communication, "amplitude modulation" refers to encoding a wave with information by adjusting the height (amplitude) of the waves. <em>(a)</em>