using if condition gives an error" the condition has length > 1 and only the first element will be used"

I am new to R language. I am trying to create a new variable in my dataset using if condition on another variable which is numeric data type

my code:

new_data$time_index<-if(new_data$time_n>0 & new_data$time_n<=40000{new_data$time_index<-.1}

error message:

the condition has length > 1 and only the first element will be used

Does anybody know what is causing this error?