How does a physicist answer a scientific question?

Consider the following statements about Newton's 2nd law in general. Select all of the statements that are true. Note, there may

Art [367]

Answer:

1. True

2. False

3. True

Explanation:

Newton's 2nd law states that the net force exerted on an object is equal to the product between the mass of the object and its acceleration:

$\sum F = ma$ (1)

where

$\sum F$ is the net force on the object

m is its mass

a is the acceleration

Furthermore, we know that acceleration is defined as the rate of change of velocity:

$a = \frac{dv}{dt}$

So let's now analyize the three statements:

1. A net force causes velocity to change: TRUE. Net force (means non-zero) causes a non-zero acceleration, which means that the velocity of the object must change.

2. If an object has a velocity, then we can conclude that there is a net force on the object: FALSE. The fact that the object has a velocity does not imply anything about its acceleration: in fact, if its velocity is constant, then its acceleration is zero, which would mean that the net force on the object is zero. So this statement is not necessarly true.

3. Accelerations are caused by the presence of a net force: TRUE. This is directly implied by eq.(1): the presence of the net force results in the object having a non-zero acceleration.

8 0

2 years ago

About how long does it take ocean water to travel around a gyre?

mylen [45]

The Gulf Stream, for example, has an average speed of 4 mph, or 100 miles/day, or 3600 miles/year, in round numbers. A complete circuit around the Atlantic is 8 or 10 thousand miles, which would take around 3 years on a raft.

4 0

3 years ago

A car is running at a velocity of 50 miles per hour and the driver accelerates the car by 10 miles per hour square.How far the c

krek1111 [17]

It will be 80 miles and it can be done only in 16 min

7 0

2 years ago

Read 2 more answers

Suppose you are drinking root beer from a conical paper cup. The cup has a diameter of 10 centimeters and a depth of 13 centimet

sveta [45]

Answer:

The level of the root beer is dropping at a rate of 0.08603 cm/s.

Explanation:

The volume of the cone is :

$V=\frac {1}{3}\times \pi\times r^2\times h$

Where, V is the volume of the cone

r is the radius of the cone

h is the height of the cone

The ratio of the radius and the height remains constant in overall the cone.

Thus, given that, r = d / 2 = 10 / 2 cm = 5 cm

h = 13 cm

r / h = 5 / 13

r = {5 / 13} h

$V=\frac {1}{3}\times \frac {22}{7}\times ({{{\frac {5}{13}\times h}}})^2\times h$

$V=\frac {550}{3549}\times h^3$

Also differentiating the expression of volume w.r.t. time as:

$\frac {dV}{dt}=\frac {550}{3549}\times 3\times h^2\times \frac {dh}{dt}$

Given: $\frac {dV}{dt}$ = -4 cm³/sec (negative sign to show leaving)

h = 10 cm

So,

$-4=\frac{550}{3549}\times 3\times {10}^2\times \frac {dh}{dt}$

$\frac{55000}{1183}\times \frac {dh}{dt}=-4$

$\frac {dh}{dt}=-0.08603\ cm/s$

<u>The level of the root beer is dropping at a rate of 0.08603 cm/s.</u>

3 0

2 years ago

How does energy change (transforms) as the mass is dropping?

olganol [36]

Answer:

Mass has total mechanical energy, which is the sum of kinetic and potential energy. as the mass is dropping, potential energy is converted into kinetic energy so mechanical energy is preserved If there is no friction. If there is friction, some of the mechanical energy is lost as heat energy so it changes.

Explanation:

4 0

3 years ago