What heat transfer are uv rays from the sun. Radiation, conduction, or convection

A ball with a horizontal speed of 1.0m/s rolls off a bench 2.0 m high. (a) how long will the ball take to reach the floor? (b) h

bixtya [17]

The motion of the ball is a composition of two motions:
- on the x (horizontal) axis, it is a uniform motion with initial velocity $v_x = 1.0 m/s$
- on the y (vertical) axis, it is a uniformly accelerated motion with acceleration $g= 9.81 m/s^2$

(a) to solve this part, we just analyze the motion on the vertical axis. The law of motion here is
$y(t) = h - \frac{1}{2} gt^2$
By requiring y(t)=0, we find the time t at which the ball reaches the floor:
$h- \frac{1}{2}gt^2=0$
$t= \sqrt{ \frac{2h}{g} }= \sqrt{ \frac{2\cdot 2.0 m}{9.81 m/s^2} }=0.64 s$

(b) for this part, we can analyze only the motion on the horizontal axis. To find how far the ball will land, we must calculate the distance covered on the x-axis, x(t), when the ball reaches the ground (so, after a time t=0.64 s):
$x(t) = v_x t = (1.0 m/s)(0.64 s)=0.64 m$

4 0

3 years ago

A 78.5-kg man is standing on a frictionless ice surface when he throws a 2.40-kg book horizontally at a speed of 11.3 m/s. With

kirill [66]

Answer:

The man moves across the ice with a speed of 0.345m/s.

Explanation:

From the conservation of linear momentum, we have that the total linear momentum before the book throw is equal to the total linear momentum just after it. Since the initial velocity of the system is zero (so the initial momentum is zero), we have that:

$m_mv_m+m_bv_b=0\\\\v_m=-\frac{m_b}{m_m} v_b$

Where $m_m$ is the mass of the man, $m_b$ is the mass of the book, and $v_m$ and $v_b$ are their velocities. Plugging in the given values, we can compute the speed of the man (ignoring the negative sign, because we care about the magnitude, not the direction):

$v_m=\frac{2.40kg}{78.5kg}(11.3m/s)=0.345m/s$

In words, the resulting speed of the man is 0.345m/s.

8 0

2 years ago

Read 2 more answers

A 45 kg wagon is being pulled with a rope that makes an angle of 38 degrees with the horizontal. The applied force is 410 N and

mel-nik [20]

Answer:

7.35m/s²

Explanation:

From the question we are not told what to find but we can as well find the acceleration of the wagon.

According to newton second law of motion

$\sum F_x = ma_x\\Fm - Ff = ma_x\\Fm - \mu R = ma_x\\Fm- \mu mg = ma_x\\$

Fm is the moving force = 410N

$\mu$ is the coefficient of friction = 0.18

m is the mass = 45kg

g is the acceleration dur to gravity = 9.8m/s²

a is the acceleration of the wagon

Substitute the given data into the equation ang get ax

$Fm- \mu mg = ma_x\\410 - (0.18)(9.8)(45) = 45a_x\\410 - 79.38 = 45a_x\\330.62 = 45a_x\\a_x = 330.62/45\\a_x = 7.35m/s^2\\$

Hence the acceleration of the wagon is 7.35m/s²

8 0

2 years ago

Ifa truck starts from rest and it has acceleration of 4 m/s for 5 second

yan [13]

Answer:

Distance 50m

final velocity 20ms^-1

$s = ut + \frac{1}{2} a {t}^{2} \\ = 0 \times t + \frac{1}{2} \times 4 \times {5}^{2} = 50m$

$v = u + at \\ v = 0 + 4 \times 5 \\ v = 20ms^{ - 1}$

6 0

2 years ago

A spinning satellite begins to unfold two solar panels as shown. How does a satellites ANGULAR MOMENTUM change as its panels ext

Soloha48 [4]

As the satellite panels extend, the angular velocity decreases due to drag force, and hence it will cause a decrease in the angular momentum of the satellite.

<h3>What is angular momentum?</h3>

Angular momentum is defined as the quantity of rotation of a body, which is the product of mass, velocity and radius.

L = mvr

L = mωr²

where;

m is mass of the object
v is velocity
r is radius
ω is angular velocity

As the satellite panels extend, the angular velocity decreases due to drag force, and hence it will cause a decrease in the angular momentum of the satellite.

Learn more about angular momentum here: brainly.com/question/4126751

#SPJ1

6 0

1 year ago