Physics MCQ series - 29

Phy-Q,

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281:  For the hydrogen atom, which series describes electron transitions to the N = 2 orbit?  Is it the:

w)  Lyman series

x)  Paschen series

y)  Balmer series

z)  Pound series

ANSWER:  Y -- BALMER SERIES

282:  The unit of mass in the English system of measure is which of the following?

w)  Pound

x)  Gram

y)  Slug

z)  Dyne

ANSWER:  Y --  SLUG

283:  What law asserts that it makes no difference in what grouping we add vectors?

ANSWER:  ASSOCIATIVE LAW OF VECTOR ADDITION

284:  A ball is thrown vertically upwards from the ground with a speed of 80 feet/second.  In the English system of units, what is the magnitude and direction of the acceleration of the ball?

ANSWER:  32 FEET PER SECOND SQUARED   DOWN or TOWARDS THE EARTH

285:  A baseball bat strikes a ball with a force of 30 Newton’s.  If the ball was in contact with the bat for 1/10 of a second, what impulse did the ball receive?

ANSWER:  3 NEWTON-SECONDS

286:  A pendulum which is suspended from the ceiling of a railroad car is observed to hang at an angle of 10 degrees to the left of vertical.  Which of the following answers could explain this phenomena?

w) The railroad car is at rest.

x) The railroad car is accelerating to the left.

y) The railroad car is moving with constant velocity to the right.

z) The railroad car is accelerating to the right.

ANSWER:  Z -- THE RAILROAD CAR IS ACCELERATING TO THE RIGHT.

287:  At time t=0, a body has a velocity of 5 meters per second, EASTWARD; at time t=2 seconds, its velocity is 7 meters per second WESTWARD.  What is the MAGNITUDE of the body's average acceleration?

ANSWER:  6 METERS PER SECOND SQUARED

288:  A man exerts a northward force of 100 Newton’s on a 50 kilogram box which sits on a level floor.  If the frictional force is 80 Newton’s, what is the magnitude of the northward acceleration of the box?

ANSWER:  0.4 METERS PER SECOND SQUARED

289:  Newton's second law states that the net force acting on a body is equal to the body's time rate of change of:

w) Acceleration

x) Mass

y) Momentum

z) Inertia

 ANSWER:  Y -- MOMENTUM

290:  A girl throws a ball vertically upward, what is the MOMENTUM of the ball at its highest point?

ANSWER:  ZERO