An object is placed at a distance 30cm from a thin lenses of power 4 diaptor. Discuss the nature of image

Friction depends on the types of surfaces involved and how hard the surfaces push together. Please select the best answer from t

LenKa [72]

True: Friction depends on the types of surfaces involved and how hard the surfaces push together.

5 0

2 years ago

Describe a situation in which an electron will be affected by an external electric field but will not be affected by an external

irina [24]

Answer:

Explanation:

Situations in which an electron will be affected by an external electric field but will not be affected by an external magnetic field

a ) When an electron is stationary in the electric field and magnetic field , he will be affected by electric field but not by magnetic field. Magnetic field can exert force only on mobile charges.

b ) When the electron is moving parallel to electric field and magnetic field . In this case also electric field will exert force on electron but magnetic field field will not exert force on electrons . Magnetic field can exert force only on the perpendicular component of the velocity of charged particles.

Situations when electron is affected by an external magnetic field but not by an external electric field

There is no such situation in which electric field will not affect an electron . It will always affect an electron .

6 0

3 years ago

Jimmy is standing 300 feet away from a rocket that is being shot up into the air away from him at an angle of elevation of 70 de

ira [324]

Answer: Vertical height of rocket is 824.24ft

Explanation: see attachment.

Opp/ Adj = Tan 70°

h/ 300 = Tan 70°

h= 300tan 70°

h = 824.24ft

4 0

3 years ago

In unit-vector notation, what is the torque about the origin on a particle located at coordinates (0 m, −3.0 m, 2.0 m) due to fo

irinina [24]

Answer:

The torque about the origin is $2.0Nm\hat{i}-8.0Nm\hat{j}-12.0Nm\hat{k}$

Explanation:

Torque $\overrightarrow{\tau}$ is the cross product between force $\overrightarrow{F}$ and vector position $\overrightarrow{r}$ respect a fixed point (in our case the origin):

$\overrightarrow{\tau}=\overrightarrow{r}\times\overrightarrow{F}$

There are multiple ways to calculate a cross product but we're going to use most common method, finding the determinant of the matrix:

$\overrightarrow{r}\times\overrightarrow{F} =-\left[\begin{array}{ccc} \hat{i} & \hat{j} & \hat{k}\\ F1_{x} & F1_{y} & F1_{z}\\ r_{x} & r_{y} & r_{z}\end{array}\right]$