What is a hypothesis?

You want to move a 4- kg bookcase to a different place in the living room. If u push with a force of 65 n and the bookcase accel

IrinaK [193]

Answer:

1.65

Explanation:

The equation of the forces along the horizontal direction is:

$F-F_f = ma$ (1)

where

F = 65 N is the force applied with the push

$F_f$ is the frictional force

m = 4 kg is the mass

$a=0.12 m/s^2$ is the acceleration

The force of friction can be written as $F_f = \mu R$ (2), where

$\mu$ is the coefficient of kinetic friction

R is the normal force exerted by the floor

The equation of forces along the vertical direction is

$R-mg=0$ (3)

since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find

$F-\mu mg = ma$

And solving for $\mu$ ,

$\mu = \frac{F-ma}{mg}=\frac{65-(4)(0.12)}{4(9.8)}=1.65$

7 0

3 years ago

Why do different stars have different life cycles

lana66690 [7]

The answer is shape is determined. A stars life cycle is determined in its size

3 0

3 years ago

An electron moving at right angles to a 0.1 T magnetic field experiences an acceleration of 6 × 1015 m.s-2. What is the speed of

GaryK [48]

Explanation:

It is given that,

Magnetic field, B = 0.1 T

Acceleration, $a=6\times 10^{15}\ m/s^2$

Charge on electron, $q=1.6\times 10^{-19}\ C$

Mass of electron, $m=9.1\times 10^{-31}\ kg$

(a) The force acting on the electron when it is accelerated is, F = ma

The force acting on the electron when it is in magnetic field, $F=qvB\ sin\theta$

Here, $\theta=90$

So, $ma=qvB$

Where

v is the velocity of the electron

B is the magnetic field

$v=\dfrac{ma}{qB}$

$v=\dfrac{9.1\times 10^{-31}\ kg\times 6\times 10^{15}\ m/s^2}{1.6\times 10^{-19}\ C\times 0.1\ T}$

v = 341250 m/s

or

$v=3.41\times 10^5\ m/s$

So, the speed of the electron is $3.41\times 10^5\ m/s$

(b) In 1 ns, the speed of the electron remains the same as the force is perpendicular to the cross product of velocity and the magnetic field.

7 0

3 years ago

Can you help me on this please

Vikentia [17]

Answer: the water level would rise since the pebble displaces minimal water compared to the boat.

Explanation:..........

8 0

3 years ago

What is the difference between air resistance and friction?

Vladimir [108]

Answer:Friction is a force that opposes the motion of objects; friction can cause objects to slow down. Air resistance is a type of friction. Air resistance causes moving objects to slow down. Different physical properties, such as the shape of an object, affect the air resistance on an object.

Explanation:

5 0

1 year ago