6 chapter - numericals || 9th class physics || Work and Energy problems || matric numericals.
This video is related to 6 chapter Numericals of 9th class physics ( Work and Energy ).(Punjab textbook) @fanticer
0:00. 6.1 A man has pulled a cart 🛒 through35m
applying a force of 300N. Find the work
done by the man. (10500 J)
02:03. 6.2 A block weighing 20N is lifted 6m verti-
cally upward. Calculate the potential
energy stored in it. ( 120 J)
03:52. 6.3 A car weighing 12kN has speed of
20m/s. Find it's kinetic energy.
( 240 kJ)
07:06. 6.4 A 500g stone 🪨 is thrown up with a
velocity of 15m/s. Find its
(I) P.E at its maximum height
(ii) K.E when it hits the ground
( 56.25 J, 56.25 J)
14:36. 6.5 On reaching the top of a slope 6 m
high from its bottom, a cyclist has a
speed of 1.5 m/s. Find the kinetic
energy and the potential energy of the
cyclist. The mass of the cyclist and
his bicycle 🚲 is 40kg.
( 45 J, 2400 J)
17:55. 6.6 A motor boat ⛵ moves at a steady
speed of 4m/s. Water resistance
acting on it is 4000N. Calculate the
power of its engine.
( 16kW)
20:26. 6.7 A man pulls a block with a force of
300N through 50m in 60s. Find the
power used by him to pull the block.
( 250 W)
22:16. 6.8 A 50kg man moved 25 steps up in 20
seconds. Find his power, if each step
is 16 cm high. (100 W)
26:50. 6.9 Calculate the power of a pump which
can lift 200 kg of water 💦 through a
height of 6m in 10 seconds.
( 1200 watts )
28:53. 6.10 An electric motor of 1hp is used to
run the water pump. The water pump
takes 10 minutes to fill an overhead
tank. The tank has capacity of 800
litres and height of 15 m. Find the
actual work done by the electric motor
to fill the tank. Also find the efficiency
of the system. ( 447600 J, 26.8% )