A metric tons bus is running with the velocity of 72km/hr. On seeing a boy on the road 65m ahead driver jammed on the brakes .Mention weather the accident (bus hitting the boy ) happened or not with mathmatical calculation and assuming that the boy did not move from his place.
Please answer it It's argent
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If T be the tension in the spring balance, then
Tcosθ=mg
andTsinθ=
r
mv
2
On squaring and then adding,
T
2
=(mg)
2
+(
r
mv
2
)
2
Or,T=m
g
2
+
r
2
v
4
According to question, we havev=72km/h=20m/s,r=400m,m=5kg,g=10m/s
2
Putting the above values for T , we get
T=5×
10
2
×
400
2
20
4
=50.25N(approx)
Hence Spring balance reading
10
50.25
=5.025kg
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