Answer:
v = [√(g/2h)]L
Explanation:
Let v be the initial horizontal velocity, t be the time James Bond uses to jump over the ledge of length, L.
So, vt = L and t = L/v
Also, since James Bond has no initial horizontal velocity, he falls freely through the distance, h so we use the equation y - y' = ut - 1/2gt², where y = 0 (at the top of the cliff) and y' = -h, u = 0 (initial vertical velocity), g = acceleration due to gravity = 9.8 m/s² and t = the time it takes to jump off the cliff = L/v.
Substituting these values into the equation, we have
y' - y = ut - 1/2gt²
-h - 0 = 0 × t - 1/2g(L/v)²
-h = - 1/2gL²/v²
v² = gL²/2h
taking square root of both sides, we have
v = [√(g/2h)]L
So, James Bond's minimum horizontal speed is v = [√(g/2h)]L
Answer:
C) 20 m/s
Explanation:
Wave: A wave is a disturbance that travels through a medium and transfers energy from one point to another, without causing any permanent displacement of the medium itself. Examples of wave are, water wave, sound wave, light rays, radio waves. etc.
The velocity of a moving wave is
v = λf ............................ Equation 1
Where v = speed of the wave, λ = wave length, f = frequency of the wave.
Given: f = 2 Hz (two complete cycles in one seconds), λ = 10 meters
Substituting these values into equation 1
v = 2×10
v = 20 m/s.
Thus the speed of the wave = 20 m/s
The right option is C) 20 m/s
Answer:
The magnetic force can be found by using the following equation:
Let’s first deal with the magnitude, then we will figure out the direction by using the right hand rule.
The direction of the L is equal to the direction of the current. So, the direction of the L is to the right. The required force is to be pointed upward.
By the right hand rule the magnetic field should be directed towards ‘into the plane’.
Explanation:
In the questions regarding the magnetic field, the cross product and the directions of the vectors are crucial. So, you should use right-hand rule efficiently.
Right-hand rule: 
Point your four fingers (except the thumb) towards the same direction as A.
Point your palm towards the same direction as B.
Your thumb should show the direction of C.
