# Mismatch on T value obtained from t.test vs summary(lm(data)) on R

I'm doing an exercise on R about the hypothesis testing and I have the following data:

| Well depth (mts) | Water temperature (°C) |
|------------------|------------------------|
| x                | y                      |
| 600              | 200                    |
| 650              | 230                    |
| 700              | 280                    |
| 800              | 300                    |
| 800              | 310                    |
| 1000             | 350                    |
| 1000             | 330                    |
| 1000             | 360                    |
| 1500             | 410                    |


The hypothesis are:

$$H_{0}:$$ The depth does not affect the water temperature

$$H_{1}:$$ The depth DOES affect the water temperature

To achieve that, I have the following code:

well_depth <- c(600, 650, 700, 800, 800, 1000, 1000, 1000, 1500)
water_temp <- c(200, 230, 280, 300, 310, 350, 330, 360, 410)
geoterm_sys <- data.frame(well_depth, water_temp)

#lm (y ~ x, data)
lm_sist_geotem <- lm(geoterm_sys$$water_temp ~ geoterm_sys$$well_depth, data=geoterm_sys)
# Print linear model
lm_sist_geotem
# Get statistical info about the model
summary(lm_sist_geotem)


Which gives me the following information:

Residuals:
Min     1Q Median     3Q    Max
-43.78 -24.65  12.75  19.28  29.28

Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept)            113.37638   33.65544   3.369 0.011941 *