Answer:
9R
Explanation:
We know that the resistance is 
.
If we stretch the wire to a new length L2 = 3L, the cross-sectional area will also change. If the cross-sectional area doesn't change throughout the wire, we can say that:
Volume = L*A = 3L * A2 being A2 the new area after stretching the wire.
Since the volume remains the same we conclude that A2 = A/3
With this information, we calculate the new resistance:
Since , and by simple inspection of the previous equation, we get:
<em>R2 = 9*R</em>
If you are asking for the weight then the formula is F=mg where f is weight m is mass and g is acceleration due to gravity.m=52kg and g=9.8m/s2(the gravity of earth)
F=52*9.8=509.6
therefore the weight of the object is 509.6N
Answer:
11250 seconds or 187.5 mins
Explanation:
The formula to be used here is that of speed.
Speed (in m/s) = distance (meter) ÷ time (secs)
The speed provided is 32 meters per second
The distance provided will have to be converted to meters; 360 km = 360 × 1000 = 360000 meters
Thus,
32 = 360000 ÷ time
time = 360000 ÷ 32
time = 11250 seconds or 187.5 mins
It will take Naomi 11250 seconds to get to New York
The change in pitch of a train's horn as it passes while you are
standing still can be described by the Doppler effect, but that
doesn't explain it.
<u>Answer:</u>
The height of ramp = 124.694 m
<u>Explanation:</u>
Using second equation of motion,
From the question,
u = 31 m/s; s = 156.3 m, a=0
substituting values
t = 
= 5.042 s
Similary, for the case of landing
t = 5.042 s; initial velocity, u =0
acceleration = acceleration due to gravity, g = 9.81 
Substituting in 
h = 124.694 m
So height of ramp = 124.694 m
