Formula STAAR Review

A car travels a distance of 150 kilometers in 3 hours. What is the speed of the car in kilometers per hour?

• 45 km/h

• 50 km/h

• 55 km/h

• 60 km/h

Answer explanation

To find the speed, divide the distance by the time: 150 km ÷ 3 hours = 50 km/h. Therefore, the speed of the car is 50 km/h.

If a block of wood has a mass of 200 grams and a volume of 100 cm³, what is its density in g/cm³?

• 1 g/cm³

• 2 g/cm³

• 3 g/cm³

• 4 g/cm³

Answer explanation

Density is calculated as mass divided by volume. Here, density = 200 g / 100 cm³ = 2 g/cm³. Therefore, the correct answer is 2 g/cm³.

A force of 10 N is applied to an object with a mass of 2 kg. What is the acceleration of the object in m/s²?

• 2 m/s²

• 3 m/s²

• 4 m/s²

• 5 m/s²

Answer explanation

Using Newton's second law, F = ma, we can find acceleration (a) by rearranging the formula to a = F/m. Here, a = 10 N / 2 kg = 5 m/s². Thus, the correct answer is 5 m/s².

Tags

NGSS.MS-PS2-2

A cyclist travels 60 km in 2 hours. What is the cyclist's average speed?

• 20 km/h

• 25 km/h

• 30 km/h

• 35 km/h

Answer explanation

To find the average speed, divide the total distance by the total time. Here, 60 km ÷ 2 hours = 30 km/h. Thus, the cyclist's average speed is 30 km/h.

A metal cube has a volume of 8 cm³ and a mass of 64 grams. What is the density of the metal?

• 6 g/cm³

• 7 g/cm³

• 8 g/cm³

• 9 g/cm³

Answer explanation

Density is calculated as mass divided by volume. Here, density = 64 g / 8 cm³ = 8 g/cm³. Thus, the correct answer is 8 g/cm³.

A force of 15 N is applied to a 3 kg object. Calculate the acceleration.

• 3 m/s²

• 4 m/s²

• 5 m/s²

• 6 m/s²

Answer explanation

Using Newton's second law, F = ma, we can find acceleration (a) by rearranging the formula: a = F/m. Here, F = 15 N and m = 3 kg. Thus, a = 15 N / 3 kg = 5 m/s². Therefore, the correct answer is 5 m/s².

Tags

NGSS.MS-PS2-2

A car travels 180 km in 4 hours. What is the car's speed?

• 40 km/h

• 45 km/h

• 50 km/h

• 55 km/h

Answer explanation

To find the speed, divide the distance by the time: 180 km ÷ 4 hours = 45 km/h. Therefore, the car's speed is 45 km/h.

A rock has a mass of 300 grams and a volume of 100 cm³. What is its density?

• 2 g/cm³

• 3 g/cm³

• 4 g/cm³

• 5 g/cm³

Answer explanation

Density is calculated by dividing mass by volume. Here, density = 300 g / 100 cm³ = 3 g/cm³. Therefore, the correct answer is 3 g/cm³.

A force of 20 N is applied to a 4 kg object. What is the acceleration?

• 4 m/s²

• 5 m/s²

• 6 m/s²

• 7 m/s²

Answer explanation

Using Newton's second law, F = ma, we can find acceleration (a) by rearranging the formula: a = F/m. Here, F = 20 N and m = 4 kg. Thus, a = 20 N / 4 kg = 5 m/s². Therefore, the correct answer is 5 m/s².

Tags

NGSS.MS-PS2-2

A train travels 300 km in 5 hours. What is the train's speed?

• 50 km/h

• 55 km/h

• 60 km/h

• 65 km/h

Answer explanation

To find the speed, divide the distance by the time: 300 km ÷ 5 hours = 60 km/h. Therefore, the train's speed is 60 km/h.