Answer:
1.429*10^-5 m
Explanation:
From the question, we are given that
Diameter of the cable, d = 3 cm = 0.03 m
Force on the cable, F = 2 kN
Young Modulus, Y = 2*10^11 Pa
Area of the cable = πd²/4 = (3.142 * 0.03²) / 4 = 0.0028 / 4 = 0.0007 m²
The fractional length = Δl/l
Δl/l = F/AY
Δl/l = 2000 / 0.0007 * 2*10^11
Δl/l = 2000 / 1.4*10^8
Δl/l = 1.429*10^-5 m
Therefore, the fractional length is 1.429*10^-5 m long
Answer:

Explanation:
Generally the workdone in moving the proton is mathematically represented as

Where 
So

Here
is the velocity at A with value 50 m/s
So


Also

Here
is the velocity at A with value 
=> 
=>
So


Now this workdone is also mathematically represented as

So

Here 
So


Generally proton movement is in the direction of the electric field it means that 
So

Answer:
50 ms⁻¹
Explanation:
Given that,
Distance Travelled =2000 meters
Time Taken =40 seconds
velocity = ?
we know,
velocity = Distance / Time
=(2000 / 40) ms⁻¹
=50 ms⁻¹
Answer:
a) 
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
a = Acceleration

The acceleration of the bicycle and rider is -1.5 m/s²
Force

The magnitude of the average force needed to bring the bicycle and its rider to a stop is 
Answer:
1.53m
Explanation:
Given parameters:
Mass of box = 3kg
Gravitational potential energy = 45J
Unknown
Height of the box = ?
Solution:
To solve this problem;
Gravitational potential energy = mgh
m is the mass
g is the acceleration due to gravity
h is the height
45 = 3 x 9.8 x h
h = 1.53m