7 grade

A body moves from a point A to a point B with a velocity of 6 m/s and returns to point A with a speed of 8 m/s.What is the average speed?

• 5 m/s

• 6,8 m/s

• 8,9 m/s

• 7 m/s

A car travels a distance with a speed of 10 m/s in 2 min.Then another car covers same distance with a speed of 2 m/s.What will the time taken by the second car be in minutes.

• 7,3 m/s

• 5 m/s

• 10 m/s

• 10 m/min

An airplane flown at a speed of 500 km/h in 6 h.What is the distance flown by the plane in kilometres.

• 3 x 10³

• 30

• 3500

• 83,3

Which graph below represents uniform motion?

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The graph shows the change in velocity of a body with time.What is the distance covered by the body in 4s?

• 8 m

• 20 m

• 0,2 m

• 80 m

A car moves along the path given in the figure from point A to point B in 5 s. What is its average speed in metres per second,m/s?

• 5

• 8

• 10

• 6

A regular container of base area 120 cm² and height 3 cm is half-filled with water.What is the volume of the water?

• 360 ml

• 180 ml

• 100 ml

• 40 ml

A golden-colored cube is handed to you. The person wants you to buy it for $100, saying that is a gold nugget. You pull out your old geology text and look up gold in the mineral table, and read that its density is 19.3 g/cm³. You measure the cube and find that it is 2 cm on each side, and weighs 40 g. What is its density? Is it gold? Should you buy it?

• 4 g/cm³

• 7,8 g/cm³

• 5 g/cm³

• 2 g/cm³

You have a different rock with a volume of 30 cm³ and a mass of 60g. What is its density?

• 4 g/cm³

• 3 g/cm³

• 2 g/cm³

• 0,5 g/cm³

185 g copper and 103 g lead are combined to make an alloy. Calculate the density of this mixture.

(d_copper = 8.9 g / cm3 ; d_lead = 11.3 g / cm3)

• 9,6 g/cm³

• 5 g/cm³

• 20,2 g/cm³

• 2,34 g/cm³