91. A crate of weight W being pushed across a : 2102098
91. A crate of weight W is being pushed across a horizontal surface by a force directed at an angle of 20? below the horizontal. What is the magnitude of the normal force on the crate?
A. It is less than W.
B. It equals W.
C. It is more than W.
D. None of the above since the coefficient of kinetic friction is not given.
92. The net force on an object is in the positive x-direction. Consider the following statements.
(i) The object can be moving in the negative x-direction.
(ii) The object can be speeding up.
(iii) The object can be slowing down.
(iv) The object can be moving in the positive y-direction.
Which of the statements are true?
A. (i) and (ii)
B. (ii) and (iii)
C. (iii) and (iv)
D. Choose this answer if all the statements are true.
93. An object weighs 100 N. If the gravitational constant G were half of what it is currently, what would the weight of the object be?
A. 100 N
B. 50 N
C. 25 N
D. 200 N
94. Five boxes, each having weight 100 N, are stacked up. The bottom box is the fifth from the top. What is the magnitude of the normal force upward exerted by the fourth box from the top on the third box from the top?
A. 100 N
B. 200 N
C. 300 N
D. 400 N
95. A box of mass m is placed on an incline with angle of inclination q. The box does not slide. The magnitude of the frictional force in this case is:
A. ms mg sin q.
B. mg cos q.
C. mg sin q.
D. not given.