A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 tonnes.

For this question, if I solve for acceleration by using the equation a = v - u / t , then I get 1 m/s² as the acceleration. But if I use the equation, S = ut + 1/2 at² , then I get 2 m/s² as the acceleration. Since none of the formulae are wrong, why is the answer different in each case ?

SUB : BIOLOGY

DAY 1 : Prepare a model of plant cell by using household materials like rice,

plastic bottles, wires, cardboard etc..

DAY 2 : Prepare a venn diagram of plant cell and animal cell ( similarities in

middle & differences in side )

DAY 3 : Make a flow chart of Tissues ( plants and animals) by using printed

diagrams or coloured diagrams

DAY 4 : Prepare a note on Types of tissues and there location and functions in a

tabular form

Prepare a plant cell model by household materials. Like rice ,plastic,cardboard.etc."*"

The cell theory states that

• A. All cells have nuclei.
• B. All cells are totipotent.
• C. Cells reproduce by mitosis.
• D. Cells are the basic structural units of living beings.

List the point of difference between Homogeneous and Heterogeneous mixtures

Turmeric is a natural indicator. On adding its paste to acid and base separately, which color is observed?

A. yellow in both acid and base

B. yellow in acid and red in the base

C. Pink in acid and yellow in the base

D. Red in acid and blue in the base.