Through which material do P waves move the fastest?

The drag on a pitched baseball can be surprisingly large. Suppose a 145 g baseball with a diameter of 7.4 cm has an initial spee

kupik [55]

Answer:

<h2>Part A)</h2><h2>Acceleration of the ball is 10.1 m/s/s</h2><h2>Part B)</h2><h2>the final speed of the ball is given as</h2><h2> $v_f = 35.3 m/s$ </h2>

Explanation:

Part a)

As we know that drag force is given as

$F = \frac{C_d \rho A v^2}{2}$

$C_d = 0.35$

$A = \frac{\pi d^2}{4}$

$A = \frac{\pi(0.074)^2}{4}$

$A = 4.3 \times 10^{-3} m^2$

$v = 40.2 m/s$

so we have

$F = \frac{0.35\times 1.2 (4.3 \times 10^{-3})(40.2)^2}{2}$

$F = 1.46 N$

So acceleration of the ball is

$a = \frac{F}{m}$

$a = \frac{1.46}{0.145}$

$a = 10.1 m/s^2$

Part B)

As per kinematics we know that

$v_f^2 - v_i^2 = 2 a d$

$v_f^2 - 40.2^2 = 2(-10.1)(18.4)$

$v_f = 35.3 m/s$

4 0

4 years ago

Newton's first law equations like velocity and stuff like that

Klio2033 [76]

Answer:

Newton's first law: An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force. ... An object sliding across a table or floor slows down due to the net force of friction acting on the object.

Explanation:

please give me a heart

4 0

3 years ago

A force of 3kN acts on a car to make it accelerate by 1.5m/s/s. What is the mass of the car?

Masja [62]

Answer:

2

Explanation:

To find force it's force = mass times acceleration so to find mass you would divide force by acceleration

5 0

3 years ago

A thin rod of length 0.64 m and mass 120 g is suspended freely from one end. It is pulled to one side and then allowed to swing

valina [46]

Answer:

1. Kinetic Energy = 0.0161 Joules

2. Height = 0.0137m

Explanation:

Given

Length of Rod, l = 0.64m

Mass, m = 120g = 0.12kg

Angular speed, w = 1.40 rad/s

a.

Calculating the Rod's kinetic energy

This is calculated by

Kinetic Energy = ½Iw²

Where I = rotational inertia of the rod about an axis.

This is calculated as follows;

I = Icm + mh²

I = ImL² + m(L/2)²

I = 1/12 * 0.12 * 0.64² + 0.12 * (0.64/2)²

I = 0.016384 kgm²

By substituton

KE = ½Iw² becomes

KE = ½ * 0.016384 * 1.40²

KE = 0.01605632J

KE = 0.0161 Joules

2. Using the total conservation of momentum;

K + U = Kf + V

Where K = Initial Kinetic Energy of the rod at lowest point.

U = Initial gravitational potential energy of the rod at lowest point

Kf = Final Kinetic Energy of the rod at maximum height = 0 J

V = Final gravitational potential energy of the rod at maximum height

So, K + U = Kf + V become

K + U = 0 + V

K + U = V

K = V - U = mgh

substitute 0.01605632J for K

0.01605632J = mgh

h = 0.01605632J/mg

h = 0.01605632J/(0.12 * 9.8)

h = 0.013653333333333

h = 0.0137m

4 0

3 years ago

An object attached to a horizontal spring is oscillating back and forth along a frictionless surface. the maximum speed of the o

Andreas93 [3]

<span>First of all, the maximum speed occurs when the object passes through the
equilibrium position

The kinetic energy when the object has this max speed is

K= 1/2 * mass * (1.25 m/s)^2

The potential energy in the spring when the speed is equal to zero

U= 1/2 * k * xmax^2

The maximun force of the spring is

mass*acceleration = k*xmax

m * 6.89 m/s2 = k * xmax
xmax = 6.89* m / k

0.5 * m * 1.56 = 0.5 * k * xmax^2

</span>m * 1.56 = k * (<span>6.89* m / k )^2 </span>
<span>
1.56 m = 47.47 m^2 / k
m/k = 0.032862

period = 2 *pi*sqrt[m/k]
= 2 pi </span><span>sqrt [ </span><span>0.032862]
= 1.139 s

A fourth of the period elapses between the instants of max acceleration and maximum speed

= 1/4* period
= 1/4 * </span><span><span>1.139 s </span> = 0.284s </span>

7 0

4 years ago