Answer:
Explanation:
a )
change in the gravitational potential energy of the bear-Earth system during the slide = mgh
= 45 x 9.8 x 11
= 4851 J
b )
kinetic energy of bear just before hitting the ground
= 1/2 m v²
= .5 x 45 x 5.8²
= 756.9 J
c ) If the average frictional force that acts on the sliding bear be F
negative work done by friction
= F x 11 J
then ,
4851 J - F x 11 = 756.9 J
F x 11 = 4851 J - 756.9 J
= 4094.1 J
F = 4094.1 / 11
= 372.2 N
Because: Some of the work done by the machine is used to overcome the friction created by the use of the machine. ... Work output can never be greater than work input. Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work.
Answer:
Explanation:
mass of the bicycle + cyclist = 50 kg
constant speed = 6 km/h
a cyclist coasting down a 5.0° incline
the downward velocity is constant, so net acceleration must be zero
the air drag must be equal to gravitational force downward along the ramp
now for upward motion
Answer:
Construct a quadrilateral ABCD, where
Construct a quadrilateral ABCD, whereAB = 4 cm, BC = 5 cm, CD = 6.5 cm and angle B = 105° and angle C = 80°
