Answer:
18min
Explanation:
v=d/t
t=d/v= 27/90 =0.3hrs =18min
Since work is the change in kinetic energy, the efficiency of a machine can be stated as the percentage of the output work divided by the input work minus the work lost from to friction and heat. Multiply Eff by 100% to get the efficiency percentage.
Answer:
0.75 m
Explanation:
Let's call the distance between the bulb and the mirror x.
The bulb and the length of the mirror form a triangle. The mirror and the illuminated area on the floor form a trapezoid. If we extend the lines from the mirror edge to the reflected image of the bulb, we turn that trapezoid into a large triangle. This triangle and the small triangle are similar. So we can say:
x / 0.4 = (3 + x) / 2
Solving for x:
2x = 0.4 (3 + x)
2x = 1.2 + 0.4 x
1.6 x = 1.2
x = 0.75
So the bulb should located no more than 0.75 m from the mirror.
Answer:
a) True
b)False
c)False
• Had to complete the question first.
A block slides at constant speed down a ramp while acted on by three forces: its weight, the normal force, and kinetic friction. Respond to each statement, true or false.
(a) The combined net work done by all three forces on the block equals zero.
(b) Each force does zero work on the block as it slides.
(c) Each force does negative work on the block as it slides.
Explanation:
Net work is the change in kinetic energy, which leads to final kinetic energy - our initial kinetic energy this is the formula for net work. This is the working energy theorem, a theorem that states that the net work on an object induces a change in the object's kinetic energy.
Answer:
the displacement is zero and the distance is 100 meters
Explanation:
