Answer:
4.62 s
Explanation:
We are given that
Initial angular speed,
Substitute the values
Hence, the wheel takes 4.62 s to come to rest.
Answer:
Explanation:
If a baseball is hit into the air with a velocity of 27 m/s, we want to determine the maximum height of the ball. Using the projecile formula;
Max height H = u²/2g
u is the initial velocity of the body = 27m/s
g is the acceleration due to gravity = 9.81m/s²
H = 27²/2(9.81)
H = 729/19.62
H = 37.16m
Hence the ball went 37.16m high
Answer:
- 5436 J
Explanation:
mass of car, m = 120 kg
radius of loop, r = 12 m
velocity at the bottom (A) = Va = 25 m/s
Velocity at the top(B) = Vb = 8 m/s
Vertical distance from A to B = diameter of loop, h = 2 x 12 = 24 m
by use of Work energy theorem
Work done by all the forces = change in kinetic energy of the body
Work done by the force + Work done by the friction = Kinetic energy at B - kinetic energy at A
- m x g x h + Work done by friction = 0.5 x 120 x (Vb^2 - Va^2)
- 120 x 9.8 x 24 + Work done by friction = 60 x (64 - 625)
- 28224 + Work done by friction = - 33660
Work done by friction = -33660 + 28224 = - 5436 J
Normal humans can withstand no more than 9 g's, and even that for only a few seconds. When undergoing an acceleration of 9 g's, your body feels nine times heavier than usual, blood rushes to the feet, and the heart can't pump hard enough to bring this heavier blood to the brain.
Answer:
None, both objects will hit ground at the same time.
Explanation:
- Assuming no air resistance present, and that both objects start from rest, we can apply the following kinematic equation for the vertical displacement:
- As the left side in (1) is the same for both objects, the right side will be the same also.
- Since g is constant close to the surface of the Earth, it's also the same for both objects.
- So, the time t must be the same for both objects also.