The pressure exerted by a column of liquid of height h and density ρ is given by the hydrostatic pressure equation p = ρgh, where g is the gravitational acceleration.
p = ρghρ = 1000 kg/m3g = 9.81 m/s2convert mm h20 to Pa700 mm H20 ( 9.81 pa / 1 mm h2o)= 6867 Pa
6867 Pa = (1000 kg/m3)(9.81 m/s2)hh = 0.7 mh = 700 mm
Option C is the correct answer
The dummy is moving with a speed 0 km/h relative to the seat in which it is sitting.
If the relative speed was non-zero, the dummy would move away from its seat, which contradicts the problem formulation.
Answer
given,
mass of steel ball, M = 4.3 kg
length of the chord, L = 6.5 m
mass of the block, m = 4.3 Kg
coefficient of friction, μ = 0.9
acceleration due to gravity, g = 9.81 m/s²
here the potential energy of the bob is converted into kinetic energy
v = 11.29 m/s
As the collision is elastic the velocity of the block is same as that of bob.
now,
work done by the friction force = kinetic energy of the block
d = 7.23 m
the distance traveled by the block will be equal to 7.23 m.
Mass (m)=55kg
acceleration (a)=9.81 m/s^2, this is the acceleration due to gravity.
initial velocity=0m/s. The skydiver doesn’t start with any speed because she is on the plane or helicopter.
final velocity=16m/s This is the velocity (speed) the skydiver reaches
The equation we use is KE=.5mv^2
Kinetic energy=.5 mass x velocity^2
KE=.5(55kg)(16m/s)^2
KE=.5(55kg)(256m/s)
KE=.5(14080J)
J=Joules
KE=7040J
Kinetic energy is 7040 Joules (J)
Hope this helps
