Physics Conceptual Questions
For a constant linear acceleration, the velocity v time graph is
A non-horizontal and non-vertical straight line
A cannon launches two projectiles with the same initial speed. Projectile A is launched at 20 degrees above the horizontal. projectile B is launched at 70 degrees above the horizontal. Which projectile spends more time in the air?
Projectile B (70 degrees)
For a projectile launched horizontally, the horizontal component of its velocity...
Remains a non-zero constant (Vx = Vxo)
Which of the following is a scalar quantity?
Work and kinetic energy
Impulse
Has the same units as momentum
If you want to cross a river in a boat in the least amount of time, you should...
Head straight across the river
You hit a golf ball. When the ball reaches its maximum altitude, its velocity is...
Horizontal
You throw a tennis ball to your friend, who catches it at the same height it was released from. The ball reaches its maximum altitude
In half the time it is in the air
An acceleration may result from
Increase in speed, decrease in speed or a change in direction
The coefficient of kinetic friction
Is usually smaller than the coefficient of static friction
The prefix giga- means?
10^9
How many sig figs does 300.0 m/s have
4
In the absence of air resistance, at what launch angle should a cannon be aimed in order to reach the greatest range?
45
The action reaction forces of newtons 3rd law
Act on different objects
The free fall motion described in this section applies to
An object dropped from rest, and object thrown vertically downward, and an object thrown vertically upwards upwards.
A vector quantity has
Both direction and magnitude
A change in gravitational potential energy...
Depends only on the initial and final positions
The acceleration of an object is
Directly proportional to the net force and inversely proportional to its mass
An object is thrown straight upward. At its maximum height
Its velocity is zero
A unit vector has
Magnitude and direction
What are the base units for length, mass and time in the SI system?
Mass, Kilogram and seconds
A pitcher throws a fastball, when the catcher catches it..
Negative work is done
Give 2 examples of derived units in the SI system
Newtons and Liters
You move a heavy object by pushing on a handle that is attached to the object at an angle. Compare the normal force on the object to the weight force on the object.
Normal force is greater than the weight
A scalar quantity has
Only magnitude
The net force of an object is zero. Which of the following statements is most correct?
The object is either at rest or moving at a constant velocity
A cannon launches two projectiles with the same initial speed. Projectile A is launched at 20 degrees above the horizontal. projectile B is launched at 70 degrees above the horizontal. Which projectile travels a greater horizontal distance?
Same distance
Two marbles roll simultaneous off either side of a table. Both marbles leave the edge of the table at the same time, but with different velocities. Which marble hits the ground first?
Same time
Distance is to displacement as
Speed is to velocity
two springs are identical except for their spring constants k2 > k1. If the same force is used to stretch the springs,
Spring 1 will be stretched farther than spring 2
Which of the following is not a unit of power
Watts x seconds
You apply the same force to a car and a truck. The truck has two times the mass of the car.
The car will have twice the acceleration of the truck
Impulse is equal to
The change in momentum
Unit analysis of an equation can tell you if
The equation is dimensionally correct
A 25,000 kg truck collides with a 2,500 kg car. Compare the force exerted on the car(by the truck) to the force exerted on the truck(by the car).
The force on the truck is the same as the force on the car (equal and opposite reactions)
If a nonconservative force acts on an object, and does work, then
The mechanical energy is not conserved
Two identical twins with the same mass take the stairs to the second floor of a house. Twin A gets there in 30s; Twin B gets there in 15s. Which twin did more work against gravity? Which twin used more power?
Twin B
The force required to keep a rocket ship moving at a constant velocity in deep space is
Zero
The reference point for gravitational potential energy may be
Zero, negative or positive
