Let denote the position vector of the ball hit by player A. Then this vector has components
where is the magnitude of the acceleration due to gravity. Use the vertical component to find the time at which ball A reaches the ground:
The horizontal position of the ball after 0.49 seconds is
So player B wants to apply a velocity such that the ball travels a distance of about 12 meters from where it is hit. The position vector of the ball hit by player B has
Again, we solve for the time it takes the ball to reach the ground:
After this time, we expect a horizontal displacement of 12 meters, so that satisfies
The distance is increasing as time passes.
Answer:
2
Explanation:
length of the raft, L = 2 m
Width of the raft, W = 2.5 m
height of the raft, H = 9.8 cm = 0.098 m
mass of each person, m = 75 kg
Density of wood = 650 kg/m^3
volume of raft, V = L x W x H = 2 x 2.5 x 0.098 = 0.49 m^3
let there are N persons
According to the principle of floatation
Buoyant force acting on the raft = True weight of the raft
Volume x density of water x g = volume x density of wood x g + N x mg
0.49 x 1000 x g = 0.49 x 650 x g + N x 75 x g
490 = 318.5 + N x 75
N = 2.28
So, the maximum number of person is 2.
Answer:
The string must support the tension of 392 N.
Explanation:
The tension that the string must support should equal the centripetal force exerted on the on the stone as it goes in a circular path (because if the string supported less tension, it would break).
The centripetal force exerted on the stone is
where
<em>v</em> = velocity of the stone in m/s
<em>m</em> = mass of the stone in kg
<em>R</em> = radius of the circular path.
Now the velocity of the stone is 7.00 m/s, the mass of the stone is 4000g or 4 kg (1000 g = 1kg), and the radius of the circular path is just the length of the string, and it is 50 cm or 0.5 m (100cm =1m); therefore, we get
m = 4kg
v =7m/s
R = 0.5m.
We put these values into the equation for the centripetal force and get:
The centripetal force is 392 Newtons, and therefore, the tension that the string must support mus be 392 N.
Answer
The answer and procedures of the exercise are attached in the following archives.
Step-by-step explanation:
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.