Answer: 0.5 seconds or 2.625 seconds
Explanation:
At t = 0, The ball is 4 ft above the ground.
The height of the football varies with time in the following way:
s(t) = -16 t² + 50 t + 4
we need to find the time in which the height would of the football would be 25 ft:
⇒25 = -16 t² + 50 t + 4
we need to solve the quadratic equation:
⇒ 16 t² - 50 t + 21 = 0

⇒ t = 0.5 s or 2.625 s
Therefore, at t = 0.5 s or 2.625 s, the football would be 25 ft above the ground.
Answer:
C. The floor pushing back against the foot
Explanation:
Answer:

Explanation:
we know that
The formula to calculate the acceleration is

we have



substitute


Answer:


Explanation:
Given that
Q= 5 L/min
1 L = 10⁻³ m³/s
1 min = 60 s
Q=0.083 x 10⁻³ m³/s
d= 6 μm
v= 1 mm/s
So the discharge flow through one tube
q = A v


A=2.8 x 10⁻¹¹ m²
v= 1 x 10⁻³ m/s
q= 2.8 x 10⁻¹⁴ m³/s
Lets take total number of tube is n
Q= n q
n=Q/q


Surface area A
A= π d L


Answer:
0.45 m/s in the negative x-direction
Explanation:
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where
is the common velocity,
and
are velocities of magnet moving in positive x-direction and magnet moving in negative x-direction respectively,
and
are masses of magnet moving in positive x-direction and magnet moving in negative x-direction respectively.
Substituting 125 g for
and 85 g for
, 7.33 m/s
, -11.9 m/s for
then



Therefore, the velocity of single unit is 0.45 m/s in the negative x-direction