Physics second exam 2

The adjacent figure shows a setup of three masses that are connected by three wires. The whole system is under static equilibrium. If m1 = 10 kg, m2 = 20 kg and m3 = 30 kg, The tension (T1) in the first wire (measured in Newtons) is:

• 98

• 588

• 196

• 392

• 294

The figure to the right shows a mass 15-kg at rest and hanging from a vertical rope which is also hanging from two ropes. The tension T (in N) in the vertical rope is:

• 15

• 147

• 127

• 0

• 50

Three equal mass blocks each of mass m = 2 kg can move together over a horizontal frictionless surface. Two forces F1 = 40 N and F2 = 10 N are applied on the three masses system as shown in the figure the magnitude of the net force on the middle mass (in N) is:

• 3.3

• 10

• 30

• 6.7

• 0

In the figure shown M = l0 kg and m = 4 kg. The coefficient of kinetic friction between the inclined surface and mass m is µk = 0.3. Given that the system started from rest, find the speed (in m/s) of mass M when it has fallen a distance of 2 m.

• 2.96

• 3.6

• 4.42

• 3.96

• 2.1

If the coefficient of kinetic friction (µk ) =0.2 , then the acceleration (in m/s^2 ) of the block is:

• 13.2

• 1

• 3.33

• 0

• 10.8

A small ball of mass is suspended from a string of length L The ball revolves with constant speed v in the horizontal circle of radius r as shown in the adjacent. if the string makes an angle θ with the vertical direction, the speed v of the ball is given by:

A 2-kg object is held stationary on a wall by a horizontal force F as shown. The static coefficient of friction between the object and the wall is 0.5. What is the minimum force required to hold the object from sliding down?

• 39.2 N

• 23.5 N

• 9.8 N

• 49 N

• 19.6 N

A small object of mass m starts at rest at the position shown and sides along the frictionless (loop –the-loop) track of radius R what is the smallest value of ( y ) such that the object will slide without contact with the track?

• R/2

• R/4

• R

• 2R

• 0

A skier starts with an initial speed vi = 10 m/s at the bottom of a rough steady upward 30° inclined plane as shown. The skier travels a distance of 6 m along the plane before coming to rest. The value of the coefficient of kinetic friction is:

• 0.17

• 1.55

• 0.7

• 0.4

• 0.91

If the block shown slides from rest from point A and comes to complete stop against the spring at point B after moving 3 meters, then amount the spring has been compressed (in m) is:

• 0.5

• 0.2

• 0.3

• 0.46

• 0.11

A particle of mass m=5 kg is released from rest at Point A and slides on the frictionless truck shown in the adjacent figure if hA = 15 m and hB = 4 m The practical’s speed in m/s at point B is :

• 20

• 8.3

• 13.5

• 11.7

• 14.7