Physics 1 Actual Exam2 Questions with 100% Correct Answers

Physics 1 Actual Exam2 Questions with 100%
Correct Answers
A loaded spring shoots a ball across a flat table. After the ball is no longer in contact with the
spring the acceleration of the ball will:
A) increase linearly
B) remain constant
C) increase exponentially
D) decrease linearly

Once the ball is released, if no friction or other forces act on the ball, it will maintain constant
velocity. It did accelerate, but only while in contact with the spring. The ball has no
acceleration, or a=0. However, because acceleration remains zero across time, B is a plausible
answer.

A 10kg block is sliding across the floor at a constant velocity of 4 m/s. The block experiences
of frictional force of 20N. A rope of negligible mass is tied to the block at its center of mass
and forms an angle of 45 degrees to the horizontal. What is the tension in the rope.
A) 29 N
B) 45 N
C) 20 N
D) 23 N

The block is not accelerating. Thus, all forces in both x and y directions must sum to zero. We
know there is a 20N frictional force opposing the sliding motion. thus, there must also be 20N
of force created by the rope in the direction opposite of the friction vector. This force is created
by the x-component of the tension in the rope. The x-component is given by Tcosθ, where θ is
45°. thus we have 20N = 0.7 T and T = 20/0.7 = 29, Answer A

Two students throw identical balls into the air with identical initial total velocities of 40 m/s.
Student A throws his ball at a 50° angle with respect to the ground and Student B throws his
ball at a 40° angle. In comparison to Student A's ball, Student B's ball will:

,A) remain in the air for a longer period of time, but travel a smaller horizontal distance
B) remain in the air for a shorter period of time, but travel the same horizontal distance
C) remain in the air for a longer period of time and travel a greater horizontal distance
D) remain in the air for a shorter period of time, but travel a greater horizontal distance.

B. When comparing two projectiles with the same initial velocity:


⊗ The larger the angle, the longer the projectile is in the air.


⊗The farther the angle is from 45°, the shorter the distance traveled.

Is mass a scalar or vector quantity?

mass is a scalar quantity

Is temperature a scalar or vector quantity?

temperature is a scalar quantity

Is velocity a scalar or vector quantity?

vector quantity

Is speed a scalar or vector quantity?

scalar quantity

Is displacement a scalar or vector quantity?

vector quantity

Is acceleration a scalar or vector quantity?

vector quantity

Is force a scalar or vector quantity?

, Forces are vectors and can thus sum to zero. This is called "no net force" and is the same as if
no force existed at all. If one of those equal and opposite forces is suddenly changed, a net
force is instantly created.

Is work a scalar or vector quantity?

scalar quantity

Is energy a scalar or vector quantity?

scalar quantity

Is charge a scalar or vector quantity?

scalar quantity

Is electric field a scalar or vector quantity?

vector quantity; all fields are vectors

Is magnetic field a scalar or vector quantity?

vector quantity; all fields are vectors

Is time a scalar or vector quantity?

scalar quantity

Is density a scalar or vector quantity?

scalar quantity

Is torque a scalar or vector quantity?

vector quantity

When multiplying two vectors, if the answer is a scalar (i.e., work) you must also multiply by ?

cosθ
(i.e., W=Fdcosθ)