Answer:
Explanation:
mass of the fellow ( m ) = 66kg
acceleration of fellow a
v = u + at
4.5 = 0 + a x 2
a = 4.5 /2
= 2.25 m / s²
Net force acting on fellow in upward direction by the surface of elevator
R - mg where R is reaction force of the surface of the elevator
Applying Newton's law of motion
R - mg = ma
R = m (g +a )
= 66 x ( 9.8 + 2 )
= 778.8 N
This will be the scale reading .
Answer:
The tension in the string is quadrupled i.e. increased by a factor of 4.
Explanation:
The tension in the string is the centripetal force. This force is given by
m is the mass, v is the velocity and r is the radius.
It follows that , provided m and r are constant.
When v is doubled, the new force, , is
Hence, the tension in the string is quadrupled.
Answer:
Solids - Bricks , wood , Pottery, Bucket
Liquid - Water, soap, Sanitizers.
Gases - Aerosol in Deodorants, Chlorofluorocarbons in Fire extinguishers , Butane in lighters.
Given that,
Mass of the stone, m = 400 g = 0.4 kg
Initial speed, u = 20 m/s
It is climbed to a height of 12 m.
To find,
The work done by the resistance force.
Solution,
Let v is the final speed. It can be calculated by using the conservation of energy.
Work done is equal to the change in kinetic energy. It can be given as follows :
So, the required work done is 32.99 J.