Forces Penner AP1

• $\frac{mg}{F\sin\phi}$

• $\frac{f}{F\sin\phi+mg}$

• $\frac{f}{mg}$

• $\frac{mg}{f}$

• $\frac{f}{F\sin\phi-mg}$

The planet Mars exerts a gravitational force Fmars on its moon Phobos. Phobos, which has a smaller mass than Mars, also exerts a gravitational force Fphobos on Mars. Which one of these statements is true?

• Fmars>Fphobos

• Fmars<Fphobos

• Fmars=Fphobos

If m1 = 3 kg and m2 = 2 kg, when the masses are released, the acceleration is approximately:

• 1 m/s/s

• 2 m/s/s

• 4 m/s/s

• 6 m/s/s

• 8 m/s/s

• The acceleration of the blocks will vary according to their mass

• The acceleration of each block will be the same: F/m

• The net force acting on each block is the same

• The magnitude of the force on block 3m from 2m is greater than the magnitude of the force back on 2m from 3m

• The net force acting on block 3m is three times greater than the net force acting on m

A block is pushed along a horizontal, frictionless surface with horizontal force that varies with time as shown. At time t=3 seconds, the acceleration of the block is 5.0 m/s/s. The mass of the block is

• 1 kg

• 2 kg

• 3 kg

• 5 kg

• 15 kg

A 10 kg mass is suspended from a cable A and a light rigid bar B. What is the approximate tension in cable A?

• 58 N

• 173 N

• 141 N

• 246 N

• 115 N

The free-body diagram shows all of the forces acting on a box on a level surface. Which statement is correct?

• The box must be moving to the left

• The box must be accelerating to the right

• The box must be moving to the right

• The diagram must be drawn incorrectly

A force is applied to a pair of unconnected objects of mass 4m and 3m, resting on a horizontal, frictionless surface. What is the magnitude of the force between the two masses?

• Fapplied

• 2Fapplied

• 3/4 Fapplied

• 3/7 Fapplied

• 4/7 Fapplied

Two masses, M>m, are connected by a light string hanging over a pulley. When they are released, the acceleration of the masses is:

• $\left(\frac{M+m}{M-m}\right)g$

• $\left(\frac{M-m}{M+m}\right)g$

• $\left(\frac{M}{M+m}\right)g$

• $\left(\frac{m}{M+m}\right)g$

• $\left(\frac{M-m}{M}\right)g$

A block of mass m accelerates down a rough incline as shown. The acceleration of the mass is

• $mg\sin\theta-mg\cos\theta$

• $mg\sin\theta-\mu mg\cos\theta$

• $mg\sin\theta-\mu mg$

• $g\sin\theta-g\cos\theta$

• $g\sin\theta-\mu g\cos\theta$