Answer:
Explanation:
Relative to ground level it has
PE = mgh = 8(10)(5) = 400 J
Answer:
The position is 8.18cm from the mirror.
Nature is b=virtual
Size is 1.82cm
Explanation:
Note that for a convex mirror, the image distance and the focal length are negative;
Given
Object height H0 = 4cm
object distance u = 18cm
Radius of curvature R = 30cm
Since f = R/2
f = 30/2
f = -15cm
Recall that:

Since the image distance is negative, this shows that the image is a virtual image.
To get the size:

Answer:
T = 6.0 N
Explanation:
given,
mass of the cord = 0.46 Kg
length of the supports = 7.2 m
time taken to travel = 0.74 s
tension in the chord = ?
using formula for tension calculation



v = 9.73 m/s
now, calculation of tension

T = 6.0 N
The tension in the cord is equal to 6.0 N.
Answer:
They are able to balance torques due to gravity.

Explanation:
When two friends of different masses will balance themselves on see saw then at equilibrium position the see saw will remain horizontal
This condition will be torque equilibrium position where the see saw will not rotate
Here we can say

here we know that force is due to weight of two friends
and their positions are different with respect to the lever about which see saw is rotating
since both friends are of different weight so they will balance themselves are different positions as per above equation
As we know that electrostatic force between two charges is given as

here we know that electrostatic repulsion force is balanced by the gravitational force between them
so here force of attraction due to gravitation is given as

here we can assume that both will have equal charge of magnitude "q"
now we have



now we have
