GENERAL PHYSICS 1_Q1_REVIEWER

How many significant figures are in the measurement 0.004561?

• 3

• 4

• 5

• 6

Answer explanation

In the measurement 0.004561, the leading zeros are not significant. The significant figures are 4, 5, 6, and 1, totaling 4 significant figures. Therefore, the correct answer is 4.

The slope of the line of the best fit of a linearized Position-Time graph is used to calculate:_______

• Average Velocity

• Acceleration due to gravity

• Average acceleration

• Average speed

Convert 5 kilometers (km) to meters (m).

• 50 m

• 500m

• 5000m

• 50,000m

Answer explanation

To convert kilometers to meters, multiply by 1000. Therefore, 5 km x 1000 = 5000 m. The correct answer is 5000m.

Given the following set of data points: 15.8, 16.0, 15.7, 16.1, and 15.9, what is the variance?

• A. 0.020

• B. 0.025

• C. 0.015

• D. 0.030

Answer explanation

To find the variance, calculate the mean (15.8), then find the squared differences from the mean: (15.8-15.8)², (16.0-15.8)², (15.7-15.8)², (16.1-15.8)², (15.9-15.8)². The average of these gives 0.020, which is choice A.

A 10 N force is applied to an object at an angle of 30° to the horizontal, and another 8 N force is applied horizontally. What is the magnitude of the resultant force?

• A. 12 N

• B. 15 N

• C. 17 N

• D. 10 N

Answer explanation

To find the resultant force, resolve the 10 N force into components: Fx = 10 N * cos(30°) and Fy = 10 N * sin(30°). Then, combine Fx with the 8 N horizontal force and calculate the magnitude using Pythagorean theorem, yielding 17 N.

Here's a similar question:

A cyclist rides west at 25 km/h and then turns north and rides at 40 km/h. If both segments of the trip are of equal duration, what is the magnitude of the cyclist's resultant velocity?

• A. 30.5 km/h

• B. 3.5 km/h

• C. 45.2 km/h

• 
  D. 47. 2 km/h

Answer explanation

To find the resultant velocity, use the Pythagorean theorem. The cyclist travels equal times at 25 km/h and 40 km/h, giving distances of 25t and 40t. Resultant velocity = sqrt((25t)^2 + (40t)^2) / t = 47.2 km/h.

Given the following set of data points: 12.5, 12.7, 12.6, 12.8, and 12.4, what is the standard deviation?

• A. 0.10

• B. 0.15

• C. 0.20

• D. 0.25

Answer explanation

To find the standard deviation, calculate the mean (12.6), then find the squared differences from the mean, average them, and take the square root. This results in approximately 0.15, making B the correct choice.

A 15 N force is applied to an object at an angle of 45° to the horizontal, and another 10 N force is applied vertically. What is the magnitude of the resultant force?

• A. 20 N

• B. 25 N

• C. 30 N

• D. 35 N

Answer explanation

To find the resultant force, resolve the 15 N force into components: Fx = 15*cos(45°) and Fy = 15*sin(45°). Then, add the vertical 10 N force to the vertical component. Resultant = √(Fx² + (Fy + 10)²) = 30 N.

Convert 3 miles to kilometers (km).

• 4.8 km

• 5.0 km

• 4.2 km

• 6.0 km

Answer explanation

To convert miles to kilometers, multiply by 1.60934. Thus, 3 miles x 1.60934 = 4.82802 km, which rounds to 4.8 km. Therefore, the correct answer is 4.8 km.

1.    A ball is dropped from a height of 45 meters. Assuming free fall and neglecting air resistance, how long does it take for the ball to hit the ground?

• A.    2.5 seconds  

•     B.  3.0 seconds  

•     C.  3.5 seconds

•         D.  4.0 seconds

Answer explanation

Using the formula for free fall, t = sqrt(2h/g), where h = 45m and g = 9.8m/s², we find t ≈ 3.0 seconds. Thus, the correct answer is B. 3.0 seconds.