Errrrr, it has 80.
80 is the correct answer
a)
• P = F/A
P = pressure = 630 N/m^2
F = force
A = area
F = mg = 0.50 kg x 9.8 m/s^2 = 4.9 N
m= mass
g= gravity
P = F/A
A = F/P
A = 4.9 N / 630 N/m^2 = 7.778 x 10^-3 m^2
b)
• Area of a circle = pi* radius ^2
7.778 x 10^-3 m^2 = pi* radius ^2
√(7.778 x 10^-3 m^2 / pi ) = radius
radius = 0.04976 m
Answers:
a ) 7.778 x 10^-3 m^2
b) 0.04976 m
Answer:
422.36 N
Explanation:
given,
time of rotation = 4.30 s
T = 4.30 s
Assuming the diameter of the ring equal to 16 m
radius, R = 8 m


v = 11.69 m/s
now, Force does the ring push on her at the top





N = 422.36 N
The force exerted by the ring to push her is equal to 422.36 N.
The net force will point towards the acceleration of the object, as supported by Newton's second law.
Answer:
B) the change in momentum.
Explanation:
The impulse is defined as the product between the force applied on an object (F) and the duration of the collision (
):
(1)
We can rewrite the force by using Newton's second law, as the product between mass (m) and acceleration (a):

So, (1) becomes

Now we can also rewrite the acceleration as ratio between the change in velocity and change in time:
. If we substitute into the previous equation, we find

And the quantity
is equivalent to the change in momentum,
.