there is 2 word problems that i need help solving.
1) Thelma's average driving speed is 16 miles per hour faster than Kirk's. In the same length of time it takes Thelma to drive 290 miles, Kirk only drives 210 miles. What is Thelma's average speed?
2) The amount a spring will stretch, S, varies directly with the force ( or weight), F, attached to the spring. If a spring stretches 0.8 inches when 10 pounds is attached, how far will it stretch when 60 pounds is attached?
1) Thelma's average driving speed is 16 miles per hour faster than Kirk's. In the same length of time it takes Thelma to drive 290 miles, Kirk only drives 210 miles. What is Thelma's average speed?
2) The amount a spring will stretch, S, varies directly with the force ( or weight), F, attached to the spring. If a spring stretches 0.8 inches when 10 pounds is attached, how far will it stretch when 60 pounds is attached?
-
16+x = thelma's speed
x = Kirk's speed
(16+x)t = 290 (thelma's distance in t)
xt = 210 (kirks distance in t)
t = 210/x
substitute t into thelma's distance
(16+x)210 = 290x
x = 42
x+16 = 58
t must have been 5 hours
x = Kirk's speed
(16+x)t = 290 (thelma's distance in t)
xt = 210 (kirks distance in t)
t = 210/x
substitute t into thelma's distance
(16+x)210 = 290x
x = 42
x+16 = 58
t must have been 5 hours
-
y=kx
.8=k(10)
k=.08
y=.08(60)
y=4.8
.8=k(10)
k=.08
y=.08(60)
y=4.8