You pull horizontally on a 50-kg crate with a force of 450 n and the friction force on the crate is 250 n. the acceleration of the crate is

Phase changes are chemical changes. true or false

Which statements about tornadoes are true? check all that apply. (a) about 12,000 tornadoes hit the united states every year. (b) a tornado looks like a funnel. (c) tornadoes are deadly atmospheric storms that cause millions in damages each year. (d) tornadoes can reach wind speeds of more than 300 miles per hour. (e) kansas is the state with the most tornadoes. (f) you will always notice a funnel before a tornado strikes.

Can anybody me with this? ? (picture included.)