A 2000-kg sailboat experiences an eastward force of 3000 N by the ocean tide and a wind force against its sails of magnitude 6000 N directed toward the northwest (45 N of W). What is the magnitude and direction of the resultant acceleration?
[Ques. 2] A high-diver of mass 70.0 kg jumps off a board 10.0 m above the water. If, two seconds after entering the water, his downward motion is stopped, what average upward force did the water exert on him?
[Ques. 3] An object on the flat bed of a truck that is accelerating along a straight horizontal road. The coefficient of static friction is 0.300 in this case. Of the following choices, which is the lowest value of acceleration that would result in the object sliding on the bed of the truck?
a. 0.280 m/s2
b. 0.310 m/s2
c. 2.93 m/s2
d. 2.99 m/s2
e. 3.02 m/s2
[Ques. 4] Which of the following is not a fundamental force?
a. the gravitational force
b. the electromagnetic force
c. the strong force
d. the force of forward motion also known as the inertial force
e. Choose this answer if two of the named forces are not fundamental.
[Ques. 5] A book is resting on a table. How many forces would be in the free-body diagram of the book?
a. one
b. two of the same type
c. two of different types
d. three or more of the same type
e. three or more of at least two different types
[Ques. 6] Which type of force would be the equal and opposite force to a gravitational force?
a. gravitational
b. electromagnetic
c. strong
d. weak
e. It could be any one of the above or some combination of them.
[Ques. 7] When an acrobat hangs motionless from a pair of rings
a. she has no measurable weight.
b. her weight depends on the angles the ropes make with the ceiling.
c. her weight is reduced by the upward force the rings exert on her.
d. her weight is increased by the upward force the rings exert on her.
e. she exerts a gravitational force on the Earth that is equal to the sum of the forces the rings exert on her.
[Ques. 8] In order to jump off the floor, the floor must exert a force on you
a. in the direction of and equal to your weight.
b. opposite to and equal to your weight.
c. in the direction of and less than your weight.
d. opposite to and less than your weight.
e. opposite to and greater than your weight.
[Ques. 9] You hold a tennis racket in your hand. On top of the racket you have balanced a ball. Which statement is true?
a. The force of your hand on the racket and the force of the ball on the racket are equal and opposite.
b. The force of the racket on your hand and the force of the ball on the racket are equal and opposite.
c. The force of your hand on the racket and the force of the racket on the ball are equal and opposite.
d. The force of the racket on your hand and the force of the racket on the ball are equal and opposite.
e. The force of your hand on the racket and the force of the racket on your hand are equal and opposite.
[Ques. 10] You throw a ball up in the air and hold your hand under it to catch it when it comes down. The reason why the ball stops is because
a. your hand is there: your hand exerts no force on the ball.
b. your hand exerts a force on the ball perpendicular to its velocity.
c. your hand exerts a force on the ball in the direction of its velocity.
d. your hand exerts a force on the ball in the direction opposite to its velocity.
e. your hand and the ball exert forces in the same direction on each other.
Quick Reply
