Explanation:
Given that,
Mass if the rock, m = 1 kg
It is suspended from the tip of a horizontal meter stick at the 0-cm mark so that the meter stick barely balances like a seesaw when its fulcrum is at the 12.5-cm mark.
We need to find the mass of the meter stick. The force acting by the stone is
F = 1 × 9.8 = 9.8 N
Let W be the weight of the meter stick. If the net torque is zero on the stick then the stick does not move and it remains in equilibrium condition. So, taking torque about the pivot.

W = 3.266 N
The mass of the meters stick is :

So, the mass of the meter stick is 0.333 kg.
Answer:
Explanation:
Given
mass of box 
speed of box 
distance moved by the box 
coefficient of kinetic friction 
Friction force 


Kinetic Energy of box will be utilize to overcome friction and rest is stored in spring in the form of elastic potential energy




Answer:
M = 222 fringes
Explanation:
given
λ = 559 n m = 559 × 10⁻⁹ m
radius = 0.026 mm = 0.026 ×10⁻³ m
length of the glass plate = 22.1 ×10⁻² m
using relation


= 221.79
= 221 (approx.)
hence no of bright fringe
M = m + 1
= 221 +1
M = 222 fringes
For any object thrown upwards where only the force of gravity is acting upon it, uses the following formula for the maximum height attained.
H= v²/2g, where g = 9.81 m/s²
There are two information of velocities are given. However, we use the 20 m/s information because this is the launch velocity. Hence, the solution is as follows:
H = (20 m/s)²/2(9.81 m/s²)
<em>H = 20.4 m</em>