PLEASE help! This is due tomorrow, and I really need to know how to do it. A ball of mass 0.6 kg, initially at rest, is kicked directly toward a fence from a point 20 m away, as shown below.
The velocity of the ball as it leaves the
kicker’s foot is 18 m/s at angle of 58◦
above the horizontal. The top of the fence is 10m high. The kicker’s foot is in contact with the ball for 0.05 s. The ball hits nothing while in flight and air resistance is negligible. The acceleration due to gravity is 9.8 m/s^2
1.Determine the magnitude of the average
net force exerted on the ball during the kick.
Answer in units of N.
2.Determine the time it takes for the ball to
reach the plane of the fence.Answer in units of s.
3.How far above the top of fence will the ball pass?
Answer in units of m
4.What is the vertical component of the velocity when the ball reaches the plane of the fence?
Answer in units of m/s.
THANK YOU so much!!!!
See previous post: Wed, 9-9-15, 5:11 PM.
To solve these problems, we will need to use the equations of motion in two dimensions. The equations we will use are:
1. The horizontal displacement equation:
x = v0x * t
where x is the horizontal displacement, v0x is the initial horizontal velocity, and t is the time.
2. The vertical displacement equation:
y = v0y * t + (1/2) * a * t^2
where y is the vertical displacement, v0y is the initial vertical velocity, a is the acceleration due to gravity, and t is the time.
3. The vertical velocity equation:
vy = v0y + a * t
where vy is the vertical velocity, v0y is the initial vertical velocity, a is the acceleration due to gravity, and t is the time.
Let's solve each problem step by step:
1. To determine the magnitude of the average net force exerted on the ball during the kick, we need to calculate the acceleration first. We can use the equation:
a = (vf - v0) / t
where a is the acceleration, vf is the final velocity (0 m/s in this case, as the ball comes to rest), v0 is the initial velocity (18 m/s), and t is the time (0.05 s).
Once we have the acceleration, we can use Newton's second law, F = m * a, to calculate the net force exerted on the ball, where m is the mass of the ball (0.6 kg).
2. To determine the time it takes for the ball to reach the plane of the fence, we can use the horizontal displacement equation:
x = v0x * t
We know the initial horizontal velocity, v0x, from the given information (18 m/s * cos(58°)). The horizontal displacement, x, is the distance to the fence (20 m). We can solve for t.
3. To find the height at which the ball passes above the top of the fence, we need to calculate the vertical displacement at the time when the ball crosses the plane of the fence. We can use the vertical displacement equation:
y = v0y * t + (1/2) * a * t^2
We know the initial vertical velocity, v0y, from the given information (18 m/s * sin(58°)). The vertical displacement, y, is the height of the fence (10 m). We can solve for t.
4. To determine the vertical component of the velocity when the ball reaches the plane of the fence, we can use the vertical velocity equation:
vy = v0y + a * t
We know the initial vertical velocity, v0y, from the given information (18 m/s * sin(58°)). We can use the time, t, calculated in question 2, and the acceleration due to gravity, a, to find vy.