SPEED is distance divided by the change in time.
Force is change in momentum divided by the change in time.
Acceleration is change in velocity divided by the change in time.
Displacement is the straight-line distance and direction from the start-point to the end-point.
<span>the speed of something in a given direction. so i think none of these</span>
Answer:
Explanation:
Given that,
Force is downward I.e negative y-axis
F = -2 × 10^-14 •j N
Magnetic field is westward, +x direction
B = 8.3 × 10^-2 •i T
Charge of an electron
q = 1.6 × 10^-19C
Velocity and it direction?
Force in a magnetic field is given as
F = q(V×B)
Angle between V and B is 270, check attachment
The cross product of velocity and magnetic field
F =qVB•Sin270
2 × 10^-14 = 1.6 × 10^-19 × V × 8.3 × 10^-2
Then,
v = 2 × 10^-14 / (1.6 × 10^-19 × 8.3 × 10^-2)
v = 1.51 × 10^6 m/s
Direction of the force
Let x be the direction of v
-F•j = v•x × B•i
From cross product
We know that
i×j = k, j×i = -k
j×k =i, k×j = -i
k×i = j, i×k = -j OR -k×i = -j
Comparing -k×i = -j to given problem
We notice that
-F•j = q ( -V•k × B×i)
So, the direction of V is negative z- direction
V = -1.51 × 10^6 •k m/s
The rms speed of the molecules of gas A is twice that of gas B. The molecular mass of A is one fourth to that of B.
Answer: Option B
<u>Explanation:</u>
Measuring the speed of particles at a given point in time results in a large distribution of values. Some molecules can move very slowly, others very fast, and because they are still moving in different directions, the speeds may be zero. (Velocity, vector quantity that corresponds to the speed and direction of the molecule.)
To correctly estimate the average velocity, you must take the squares of the mean velocity and take the square root of this value. This is known as the root mean square (rms) velocity and is shown as follows:
Where,
M – Gas’s molar mass
R – Molar mass constant
T – Temperature (in Kelvin)
Given data is rms speed for gas molecule A is twice that of gas molecule B. So,
Therefore, equating the molecule’s rms speed formula for both A and B,
On squaring both sides, we get,
By solving the above equations, we get,