Answer: 16.3 seconds
Explanation: Given that the
Initial velocity U = 80 ft/s
Let's first calculate the maximum height reached by using third equation of motion.
V^2 = U^2 - 2gH
Where V = final velocity and H = maximum height.
Since the toy is moving against the gravity, g will be negative.
At maximum height, V = 0
0 = 80^2 - 2 × 9.81 × H
6400 = 19.62H
H = 6400/19.62
H = 326.2
Let's us second equation of motion to find time.
H = Ut - 1/2gt^2
Let assume that the ball is dropped from the maximum height. Then,
U = 0. The equation will be reduced to
H = 1/2gt^2
326.2 = 1/2 × 9.81 × t^2
326.2 = 4.905t^2
t^2 = 326.2/4.905
t = sqrt( 66.5 )
t = 8.15 seconds
The time it will take for the rocket to return to ground level will be 2t.
That is, 2 × 8.15 = 16.3 seconds
Answer:
At the lowest point in the oscillation, the momentum is zero.
At the lowest point in the oscillation, 
Explanation:
Since spring block system is performing to and fro motion along straight line
So here we can say at the lowest position of its path the velocity will become zero.
So we can say that momentum of the spring block system is given as
Also we know that after reaching the lowest point the block will again go up towards its mean position
So at the lowest point of the spring block system the block will move upwards again
So this will accelerate upwards hence
Big Bang is a theory that, as stated above, has grown to become widely acceptable scientific explanation of the origin of things. Research would say that according to this theory, the Earth originated billion years ago through an explosive of a highly energized point.
Through this explosion, the elements were formed. However, only the lightest of the elements including hydrogen and helium, with traces of lithium and beryllium. From the choices, the answer would have to be the second choice, helium.
Answer: B. helium
Answer:
3.6 seconds
Explanation:
Given:
y₀ = y = 0 m
v₀ = 31 sin 35° m/s
a = -9.8 m/s²
Find: t
y = y₀ + v₀ t + ½ at²
0 = 0 + (31 sin 35°) t + ½ (-9.8 m/s²) t²
0 = 17.78t − 4.9t²
0 = t (17.78 − 4.9t)
t = 0 or 3.63
Rounded to the nearest tenth, the ball lands after 3.6 seconds.
