9.04 Semester Test: Physics - Part 1
What additional force must be applied so that the block does not accelerate?
10 N west
A runner moving at a speed of 10.0 m/s rounds a bend with a 20.0 m radius. What is the centripetal acceleration that she experiences?
5.00 m/s²
A ball is rolling down a hill at +2.0 m/s . The ball is uniformly accelerating at +4.0 m/s² . What will the ball's velocity be 3.0 s later?
+14 m/s
On the position-time graph, what is the average velocity between 5 s and 10 s?
+4.0 m/s
A tension force of 2.50 N acts horizontally on a 2.00 kg block. The block accelerates at 0.750 m/s² . What is the force of kinetic friction?
-1.00 N
The 48 kg student on skates pushes the 40 kg student on skates. The 40 kg student accelerates at 3.0 m/s². What is the acceleration of the 48 kg student?
-2.5 m/s²
The velocity of an object increases from -5.0 m/s to -15 m/s in 2.0 s. What is the average acceleration of the object?
-5.0 m/s²
Which equation represents inverse proportionality?
y = m/x
A physical quantity X depends on mass, distance, and time. Use dimensional analysis to decide which of these is a possible expression for X where a is acceleration, v is velocity, and F is force.
X = Ft
What shape does a position vs. time graph have for an object in uniform acceleration?
quadratic
According to Einstein's explanation, what causes gravitation?
the bending of space-time by objects with mass and the associated acceleration
A diver jumps down on a springboard, bounces back up, and dives into the pool. Which of these is one of the action-reaction pairs involved?
the force the diver exerts on the water and the force the water exerts on the diver
Suppose you are on a conveyor belt walkway at an airport. The walkway is moving at 0.50 m/s . You walk backward at 0.80 m/s to hand your suitcase to a friend who is 3.0 m behind you. A security guard stands alongside the walkway watching this. What is your speed relative to the guard?
0.30 m/s
A balloon is expanded to the same volume as that of a human head. Do an order-of-magnitude estimate of the volume of this balloon in cm³.
1,000 cm³
A book is being pushed along a table at constant speed. The coefficient of static friction is 0.75, and the coefficient of kinetic friction is 0.30. The book has a mass of 0.50 kg. What is the force of friction?
1.5 N
An airplane travels southwest a distance of 650 km at a velocity of 430 km/h . How long does the trip take in hours?
1.5 h
Convert 4.9 m/s to km/h .
18 km/h
A ball is dropped from a tower. It strikes the ground with a speed of +19.0 m/s . How high is the tower?
18.4 m
A 1,560 kg car is accelerating at 1.30 m/s² . What net force acts on the car?
2,030 N
The acceleration due to gravity on the surface of Mars is gmars=3.7 m/s². How much would an 11 kg bag of potatoes weigh on Mars?
41 N
Two movers are pushing a large crate along the ground, one with a force of 30 N east and the other with a force of 40 N north. The crate does not move. What is the magnitude of the force of static friction?
50 N
A ship travels south at 15 km/h for 4 h. What is the ship's displacement in km?
60 km south
A force of 100 N acts in a direction at an angle of 30° with the x-axis. What is the magnitude of the x component of the force?
90 N
Which of the graph lines corresponds to the relation y=k/x where k is a constant?
A
Suppose the mass of each of two spherical objects is doubled, and the distance between their centers is three times as large. How is the magnitude of the force of gravity between them affected?
It is 4/9 as large.
A pendulum clock is brought to Mars. How does the bob move on Mars as compared to on Earth?
It runs slower.
Which of these is true about an object thrown straight up in the absence of air resistance?
Its acceleration is constant.
Which statement is equivalent to Newton's first law?
No net force acting on an object means no acceleration.
A 0.156 kg ice puck collides with a 0.170 kg ice puck. Both were originally moving at the same speed. Which one has the larger change in velocity?
The 0.156 kg puck changes velocity the most.
A bicycle and rider travel along a road. Which of the following statements is true?
The bicycle wheels rotate and translate the entire bike and the rider.