Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_70946 ( "Year" real, "Entrant" text, "Chassis" text, "Engine" text, "Points" real )

### Question ###
What is the sum of all the points won by Peter Whitehead in an alta f2 Chassis?

### Accurate SQL ###

SELECT SUM("Points") FROM table_70946 WHERE "Entrant" = 'peter whitehead' AND "Chassis" = 'alta f2'