Acceleration is a change in *speed* over time. In this case, the speed of the car increased by 90 km/hr in 6 s, giving it a rate of 90 km/hr/6s, or 15 km/hr/s. We’re asked for the acceleration in m/s^2, though, so we’ll need to do a few conversions to get our units straight.
There are 1000 m in 1 km, 60 min, or 60 * 60 = 3600 s in 1 hr, so we can change our rate to:
(15 x 1000)m/3600s/s, or (15 x 1000)m/3600 s^2
We can reduce this to:
(15 x 10)m/36 s^2 = 150 m/36 s^2
Which, dividing numerator and denominator by 36, gets us a final answer of roughly 4.17 m/s^2
1
2 4. 5 4 5
+3 0 7. 3 0 0
——————
3 3 1 8 4 5
line up the decimal points and add.
hope this helps!
I think it is b , that what I would i pick
Answer:
They will not meet
h-hX=1.2*g*t²
hX=v0*t-(1/2*g*t²)
Explanation:
fall h=1/2*g*t²
elevation time if v0=20 m/s te=v0/g=20 m/s /9.81 m/s²=2.0387s
hmax=v0²/(2*g)=(400 m²/s²)/19.62 m/s²2=20.387 m
free fall
t=2.0387s yields hX=1/2*g*t²=20.387 m
h-hX=200m - 20.387 m=179,613 m.
so, the second body has not enough initianoal speed to reach a meeting point
