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09/04/2019

maths homework help pleasee?!?

QUESTION
maths homework help pleasee?!?
calculate the distance travelled if
a) speed=450km/h/ time=7 min
b)speed=0.2m/sec, time =1 min
Calculate the time taken to travel
a)a distance of 16.25km at a speed of 5 km/h
b) a distance of 50km ata speed of 12 km/h
How many revolutions would a wheel of radius 1.5m take to travel 30 km (note c= pi d)
Travelling at a speed of 80 km/h a car travels between towns in 5 1/2 hours. how much time will it take to travel between these towns at 60 km/h
The express train travels its route in16 hours at an average speed of 85 km/h.
how long will it take to do the same journey at 80 km/h
how fast must it travel to do its route in 12 hours

PLEASE GUYS I NEED THIS WORK DUE IN TOMMOROW IVE HAD AN 2000 WORD ESSAY TO DO AND IVE HAD NO TIME.

ANSWER
here’s ur ans in the sequence u wrote em…

Let, speed=v, time=t, and distance=s…

1a. V=450km/h, t=7min or (7/60)hrs
v= s/t so s=v*t =450*(7/60) =52.5km (distance)

1b. V=0.2m/sec, t=1m (60sec)
s=v*t = 0.2*60= 12m (distance)

2a. s=16.25km, v=5km/h
t=s/v = 16.25/5 =3.25hrs or 3hrs 15min (time)

2b. s=50km, v=12km/h
t=50/12 = 4.17hrs

2c. let radius=r, circumference=c
s=30km, r=1.5m, c=pi*2r
c= (22/7)*(2*1.5) =9.43m
1km=1000m
30km= (30*1000)m = 30000m
no. Of revs =(30000/9.43)
=3181.34 revs

2d. v1=80km/h, t1=5(1/2)hrs
if 80km/h is done in 5(1/2)hrs
then, 60km/h will xhrs

by cross multiplying we have,
(60*5[1/2])/80 =4.125hrs or 4(1/8)hrs

3a. t=16hrs, v=85km/h, s=?
S=v*t = 85*16 =1360km

3b. t=?, v=80km/h, s=1360km
t= s/v =1360/80 =17hrs

3c. v=?, t= 12hrs, s=1360km
v=s/t =1360/12 = 113.33km/h

…good luck lizard.0sec)
s=v*t = 0.2*60= 12m (distance)

2a. s=16.25km, v=5km/h
t=s/v = 16.25/5 =3.25hrs or 3hrs 15min (time)

2b. s=50km, v=12km/h
t=50/12 = 4.17hrs

2c. let radius=r, circumference=c
s=30km, r=1.5m, c=pi*2r
c= (22/7)*(2*1.5) =9.43m
1km=1000m
30km= (30*1000)m = 30000m
no. Of revs =(30000/9.43) =3181.34 revs

2d. v1=80km/h, t1=5(1/2)hrs
if 80km/h is done in 5(1/2)hrs
then, 60km/h will xhrs

by cross multiplying we have,
(60*5[1/2])/80 =4.125hrs or 4(1/8)hrs

3a. t=16hrs, v=85km/h, s=?
S=v*t = 85*16 =1360km

3b. t=?, v=80km/h, s=1360km
t= s/v =1360/80 =17hrs

3c. v=?, t= 12hrs, s=1360km
v=s/t =1360/12 = 113.33km/h

…good luck lizard.