Q1. A worker pushes a wheelbarrow with a force of 40 N over a level distance of 6.0 m. If a frictional force of 24 N acts on the wheelbarrow in a direction opposite to that of the worker, what net work is done on the wheelbarrow?
A. 240 J
B. 216 J
C.144 J
D. 96 J
E. 75 J
Q2. Which of the following is an example of a non conservative force?
A. gravity
B. magnetism
C. friction
D. Both choices A & B are valid.
E. Both choices A & C are valid.
Q3. An amount of work equal to 1.5 J is required to compress the spring in a spring-gun. What is the "launch speed" of a 15-g marble?
A. 14 m/s
B. 15 m/s
C. 18 m/s
E. 21 m/s
F. e. 23 m/s
Q4. Lonnie pitches a baseball of mass 0.20 kg. The ball arrives at home plate with a speed of 40 m/s & is batted straight back to Lonnie with a return speed of 60 m/s. If the bat is in contact with the ball for 0.050 s, what is the impulse experienced by the ball?
A. 360 Ns
B. 20 Ns
C. 400 Ns
D. 9.0 Ns
E. 35 Ns
Q5. A 0.30-m-radius automobile tire rotates how many rad after starting from rest & accelerating at a constant 2.0 rad/s2 over a 5.0-s interval?
A. 12.5 rad
B. 25 rad
C. 2.0 rad
D. 0.50 rad
E. 0.25 rad