A dog of mass 25 kg is standing inside an elevator. The elevator is descending downward with an acceleration of 2 m/s2. What is the normal force acting on the dog from the floor?
Circle the right answers.
I. Which of the following is a vector:
A. Mass
B. Weight
C. Temperature
D. Distance
E. Speed
Ans. B
II.
A dog of mass 25 kg is standing inside an elevator. The elevator is
descending downward with an acceleration of 2 m/s2. What is
the normal force acting on the dog from the floor?
A. 245 N
B. 295 N
C. 264.6N
D. 195N
E. 225.4N
Ans. D
A football is kicked with an initial speed of 25 m/s at a certain non-zero
angle from the vertical. Which of the following statements is not
correct?
A. The horizontal component of
velocity of the football is always 25 cos q.
B. The football is moving with
the minimum speed when it reaches the highest point.
C. The football is moving with
a speed of 25 m/s when it falls back to the ground level.
D. The time required for the football
to reach its highest point equals to the time for it to return from this
highest point to the ground level.
E. The football is always accelerating
downward with an acceleration of 9.8 m/s2.
Ans. A