Classify the waves as longitudinal or transverse.

1) Little Timmy wants to measure how tall his house is. He doesn’t have a tape measure but does have a stopwatch. He recruits Bi

kifflom [539]

1) 13.7 m

The motion of the rock is a free fall, with constant acceleration g=9.8 m/s^2 towards the ground, so the total distance it covers is given by the SUVAT equation:

$S=\frac{1}{2}gt^2$

where S is the height of the house, and t is the time the rock takes to reach the ground. Substituting t=1.67 s, we find:

$S=\frac{1}{2}(9.8 m/s^2)(1.67 s)^2=13.7 m$

2) 105.5 m

The motion of the stuffed chicken is a projectile motion, with a uniform horizontal motion (with constant velocity of v=36.0 m/s) and a vertical accelerated motion (with constant acceleration of g=9.8 m/s^2).

First of all, we can find the total time of the ball by considering the vertical motion only. We know the vertical distance covered, S=42.2 m, so the time of the fall is

$S=\frac{1}{2}gt^2\\t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(42.2 m)}{9.8 m/s^2}}=2.93 s$

And now we can consider the horizontal motion to find the horizontal distance covered by the stuffed chicken:

$d=vt=(36.0 m/s)(2.93 s)=105.5 m$

3) 49.4 m

Again, the motion of the ball is a projectile motion, with a horizontal motion and a vertical motion.

The range of a projectile launched from the ground can be found by using the formula:

$d=\frac{v^2}{g} sin 2 \theta$

where, in this case:

v = 22.0 m/s is the initial velocity

$\theta=45^{\circ}$

Substituting into the formula, we find

$d=\frac{(22.0 m/s)^2}{9.8 m/s^2}(sin (2\cdot 45^{\circ}))=49.4 m$

4) 9.6 m/s^2

The frictional force acting on the monkey is given by:

$F_f = \mu mg=(0.16)(31.0 kg)(9.8 m/s^2)=48.6 N$

where $\mu$ is the coefficient of friction and m is the mass of the monkey.

We have two forces acting on the monkey: the push of F=345 N and the frictional force acting in the opposite direction. According to Newton's second law, the net force will be equal to the product between the monkey's mass and its acceleration, so we can find the acceleration:

$F-F_f=ma\\a=\frac{F-F_f}{m}=\frac{345 N-48.6 N}{31.0 kg}=9.6 m/s^2$

5) 462.3 N

The horizontal component of the pushing force is:

$F_x = F cos \theta = (648 N)(cos 25^{\circ})=587.3 N$

The frictional force, acting in the opposite direction, is

$F_f = \mu mg=(0.17)(75.0 kg)(9.8 m/s^2)=125.0 N$

where $\mu$ is the coefficient of friction and m is the mass of the box.

The net force on the box is therefore given by the net force on the horizontal direction:

$F_{net}=F_x -F_f=587.3 N -125.0 N=462.3 N$

6) 89.5 N

First of all we need to calculate the total weight of the table and the items above it.

The weight of the table is:

$W=mg=(25.0 kg)(9.8 m/s^2)=245 N$

So the total weight of the table and the items is

$W=245 N+63 N+12 N+44 N+24 N+9N+10N=407 N$

The force needed to get the table moving must be at least equal to the frictional force, which is equal to the product between the coefficient of friction and the weight of the all stuff:

$F=F_f = \mu W=(0.22)(407 N)=89.5 N$

7 0

3 years ago

An object is at rest on the ground. The object experiences a downward gravitational force from Earth. Which of the following pre

Montano1993 [528]

Answer:

A) and B) are correct.

Explanation:

If the object is at rest, it means that no net force is exerted on it.

As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.

This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).

At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.

So, the statements A) and B) are true.

6 0

3 years ago

Read 2 more answers

Properties can be observed only when the substance in a sample of matter are changing into different substance

Zolol [24]

The complete statement is "chemical properties can be observed only when the substance in a sample of matter are changing into different substance".

It states a key concept in chemistry.

A chemical property is the ability of a substance, element or compound, to transform into other substances either by decomposing or by combining with one or more substances.

This transformation is defined as chemical reaction.

During chemical reactions some chemical bonds are broken and others are formed leading to the formation of one or more different substances called products.

Some examples of chemical properties are: reactivity with oxygen, reactivity with water, acidity, basicity, oxidation, reduction. The only way to tell if a substance has certain chemical property is by letting it react and so observe the change of the original substance into one or more different substances.

8 0

3 years ago

How do scientists believe the universe formed?

Arte-miy333 [17]

Answer:

The Big Bang was the moment that the universe began, that as a tiny dense and the exploded!!!!!!! BOMBBBBBBBBBBBBBBB

Explanation:

3 0

3 years ago

Gravity is a A.pushing force B. not a force at all C. pulling force

melamori03 [73]

Answer:

C

Explanation:

gravity is a pulling force according to Newton

4 0

3 years ago