Answer:
b) 0.1 mm
Explanation:
Given that
E= 1 x 10¹⁰ N/m²
F= 4 N
d= 0.5 mm
L = 60 mm
We know that elongation due to force F given as



ΔL = 0.12 mm
Therefore the answer is -
b) 0.1 mm
The given problem can be exemplified in the following diagram:
Since there is no friction or any other external force, the only force acting in the direction of the movement is the component of the weight of the block, therefore, applying Newton's second law:

Replacing the values:

We may cancel out the mass:

Using the gravity constant as 9.8 meters per square second:

Solving the operations:

Therefore, the acceleration is 6.3 meters per square second.
The force (F) of attraction or repulsion between two point charges (Q1 and Q2) is given by the following rule:
F = <span>(k * q1 * q2) / (r^2) where:
</span>q1 and q2 are the charges
k is coulomb's constant = 9 x 10^9<span> N. m</span>2/ C<span>2
</span>r is the distance between the two charges.
Applying the givens in the mentioned equation, we find that:
F = (9 x 10^9<span> x 0.07 x 10^6 x 2) / (0.0108)^2 = 1.08 x 10^19 n </span>
Answer B. 112 m
Step-by-Step Explanation
initial velocity u = 20 m /s
final velocity v = 36 m /s
time taken t = 4 s
acceleration = (v - U) / t
= (36 - 20) / 4
a=4m/s2
from the formula
7-u2=2as , sis distance covered
putting the values
362-202=2×4×s
1296 - 400 = 8 x S
S= 112 m