A 50.0 N box is at rest on a horizontal surface. The coefficient of static friction between the box and the surface is 0.50, and the coefficient of kinetic friction is 0.30. A horizontal 20.0 N force is then exerted on the box. The magnitude of the acceleration of the box is most nearly

• 0 m/s²

• 0.5 m/s²

• 1 m/s²

• 4 m/s²

Tags

NGSS.HS-PS2-1

An archer shoots an arrow straight up with a force of 24.5 N. The arrow has a mass of 0.4 kg. What is the force of gravity on the arrow?

• 9.8 m/s²

• 9.8 N

• 61.5 N

• 3.9 N

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

A ball of mass m is suspended from two strings of unequal length as shown above. The magnitudes of the tensions T1 and T2 in the string must satisfy which of the following relations?

• T1 = T2

• T1 > T2

• T1 < T2

• T1 + T2 = mg

Tags

NGSS.HS-PS2-1

When the frictionless system shown above is accelerated by an applied force of magnitude F, the tension in the string between the blocks is

• F

• 2/3 F

• 1/2 F

• 1/3 F

Tags

NGSS.HS-PS2-1

A block of weight W is pulled along a horizontal surface at constant speed v by a force F, which acts at an angle of Ө with the horizontal, as shown above. The normal force exerted on the block by the surface has magnitude

• Greater than W

• Greater than zero but less than W

• Equal to W

• zero

Tags

NGSS.HS-PS2-1

When an object of weight W is suspended from the center of a massless string as shown above, the tension at any point in the string is

• 2W cos Ө

• ½ W cos Ө

• W/(2cos Ө)

• W/(cos Ө)

Tags

NGSS.HS-PS2-1

A block of mass 3m can move without friction on a horizontal table. The block is attached to another block of mass m by a cord that passes over a frictionless pulley, as shown above. If the masses of the cord and the pulley are negligible, what is the magnitude of the acceleration of the descending block?

• g/3

• g/4

• 2g/3

• g

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

Two people are pulling on the ends of a rope. Each person pulls with a force of 100 N. The tension in the rope is

• 0 N

• 50 N

• 100 N

• 200 N

The figure above shows a truck pulling three crates across a rough road. Which of the following shows the directions of all the horizontal forces acting on crate 2:

• 
• 
• 
• 

A 70 kg crate is pushed across a rough floor by a 500 N force exerted at 37 degrees below the horizontal, and the coefficient of kinetic friction between the crate and floor is 0.3. Which of the following is closest to the crate’s acceleration?

• 1.4 m/s²

• 2.9 m/s²

• 4 m/s²

• 5.4 m/s²

Tags

NGSS.HS-PS2-1