Answer: 100cm
Explanation:
The force of friction on a surface normal to gravity where µ is the coefficient of friction is
F = µmg
Where
F = the friction force
µ = coefficient of friction
m = mass of the object
g = acceleration due to gravity
Also, the Kinetic Energy of the object, E = Fs, where
E = Kinetic Energy
s = stopping distance. So that,
E = µmgs
40 J = 0.4 * 10 kg * 10 m/s² * s
40 J = 40 kgm/s² * s
s = 40 J / 40 kgm/s²
s = 1 m or 100 cm
Answer:
166 W
Explanation:
Power is the rate at which work is done.
The work done by Jill is the product of the weight of the pail and the height it moves.
The weight is the product of the mass and acceleration of gravity, <em>g</em>. Taking <em>g</em> as 9.81 m/s², the weight is
<em>W</em> = (6.90 kg)(9.81 m/s²) = 67.689 N
Work done = (67.689 N)(27.0 m) = 1827.603 J
Power = (1827.603 J) ÷ (11.0 s) = 166 W
<span>the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine. I would say the answer is D, but i'm not sure. :)</span>
Let the height where we are trapped is H
now to find the time to reach the key at the bottom is given as
now we have
now if the speed of sound is considered to be 340 m/s then time taken by the sound to reach at the top is given as
now the total time is given as
now by solving above equation we have
H = 48 m
now height of one floor is 3 m
so our position must be