Answer:
Explanation:
net force on the skier = mg sin 39 - μ mg cos39
mg ( sin39 - μ cos39 )
= 73 x 9.8 ( .629 - .116)
= 367 N
impulse = net force x time = change in momentum .
= 367 x 5 = 1835 kg m /s
velocity of the skier after 5 s = 1835 / 73
= 25.13 m /s
b )
net force becomes zero
mg ( sin39 - μ cos39 ) = 0
μ = tan39
= .81
c )
net force becomes zero , so he will continue to go ahead with constant speed of 25.13 m /s
so he will have speed of 25.13 m /s after 5 s .
Answer:
A- The ball has both kinetic and potential energy,
Explanation:
kinetic energy by virtue of its motion.
potential energy by virtue of its position. (It could roll off the edge of the tabel and convert gravity potential energy to kinetic energy)
Answer with Explanation:
Let rest mass
at point P at distance x from center of the planet, along a line connecting the centers of planet and the moon.
Mass of moon=m
Distance between the center of moon and center of planet=D
Mass of planet=M
We are given that net force on an object will be zero
a.We have to derive an expression for x in terms of m, M and D.
We know that gravitational force=
Distance of P from moon=D-x
=Force applied on rest mass due to m
=Force on rest mass due to mas M
because net force is equal to 0.





Let 
Then, 




b.We have to find the ratio R of the mass of the mass of the planet to the mass of the moon when x=
Net force is zero




Hence, the ratio R of the mass of the planet to the mass of the moon=4:1
Mechanical advantage is a measure of the force amplification
achieved by using a tool, mechanical device or machine system. Ideally,
the device preserves the input power and simply trades off forces
against movement to obtain a desired amplification in the output force.
The model for this is the <span>law of the lever.</span> Machine components designed to manage forces and movement in this way are called mechanisms.
An ideal mechanism transmits power without adding to or subtracting
from it. This means the ideal mechanism does not include a power source,
and is frictionless and constructed from rigid bodies that do not
deflect or wear. The performance of a real system relative to this ideal
is expressed in terms of efficiency factors that take into account
friction, deformation and wear.
Answer:
Acceleration
Explanation:
acceleration because it has magnitude but no direction