Questions about Chapter 5: Force and motion-I


Question  No:1

On Earth, an object placed on an equal-arm balance requires 12 kg to balance it. When placed on a spring scale marked in kilo-grams the scale reads 12 kg. On the Moon, where the force of gavity is (1/6) that of Earth, the new readings of the equal-arm balance (m1) and spring scale (m2) are:

A. m1=12 kg, m2=2 kg

B. m1=12 kg, m2=12 kg

C. m1=2 kg, m2=2 kg

D. m1=2 kg, m2=12 kg

E. m1=12 kg, m2=72 kg


Question  No:2

A 2.0 kg block slides down a frictionless 15 degrees inclined plane. A force (F) acting parallel to the incline is applied to the block (see figure (5)). The acceleration of the block is 1.5 m/s**2 down the incline. What is the magnitude of F?

A. 4.0 N

B. 8.1 N

C. 2.1 N

D.3.0 N

E. 8.5 N


Question  No:3

A 1.5 kg object has a velocity of (5.0 j) m/s at t=0. It is accelerated at a constant rate for 5.0 s after which it has a velocity of (6.0 i + 12 j) m/s. What is the magnitude of the net force acting on the object during this time interval?

A. 3.9 N

B. 2.8 N

C. 4.3 N

D. 1.1 N

E. 9.8 N


Question  No:4

A 3.0 kg block is pushed up a frictionless 30 degree incline by a force F=25 N, as shown in figure (6). What is the magnitude of the resulting acceleration of the block?

A. 1.7 m/s**2

B. 4.6 m/s**2

C. 3.5 m/s**2

D. 2.3 m/s**2

E. 5.1 m/s**2


Question  No:5

Three blocks (A, B, and C) rest on a table. The weight of each block is indicated in figure (7). The force of block C on block B is:

A. 9.0 N

B. 19 N

C. 14 N

D. 0.0 N

E. 5.0 N