PHYS 1425 Exam- Iclicker Question
and answers 100% correct 2025/2026
For a race car on a banked curve, what force in general is producing the centripetal acceleration for the
car? - correct answer ✔Normal Force and Friction
Which is stronger, Earth's pull on the Moon, or the Moon's pull on Earth? - correct answer ✔They pull
on each other equally
The moon does not crash into the Earth because: - correct answer ✔Its high speed of revolution keeps
it from falling to Earth
Two satellites A and B of the same mass are going around Earth in concentric orbits. The distance of
satellite B from Earth's center is twice that of satellite A. What is the ratio of the centripetal force acting
on B compared to that acting on A? - correct answer ✔1/4 (F=GmM/r^2)
Satellites speeds up as - correct answer ✔orbits decrease
Energy - correct answer ✔Ability to do work
Can friction do positive work? - correct answer ✔Yes (box on moving truck. if box moves it is friction
doing positive work)
Catcher stops a 90 mph pitch in a baseball game? What can you say about the work done by the catcher
on the ball? - correct answer ✔The catcher has done negative work.
What is the work that the Earth's gravitational force does on the moon? - correct answer ✔None
because it Fd is perpendicular.
, What is the work done by gravity on a box not moving sitting on a flat plane? - correct answer ✔0
because the force mg is perpendicular to the distance it would travel.
A golfer making a putt gives the ball an initial velocity of v0, but he has badly misjudged the putt, and the
ball only travels one-quarter of the distance to the hole. If the resistance force due to the grass is
constant, what speed should he have given the ball (from its original position) in order to make it into
the hole? - correct answer ✔2v0 or double the velocity because Work=FDcos(theta)
Work=1/2mv^2-1/2mv^2.
-FD=-1/2mv^2
D=mv^2/2F
A 1000kg car travels at 10m/s. How much work must be done on the car to stop it? - correct answer ✔-
50,000J.
W=change in kinetic energy
-1/2*1000*10^2=-50,000
An object with mass 5kg falls down from a height of 5m. What is the change in potential energy for this
object? - correct answer ✔-245J
A box sliding on a frictionless flat surface runs into a fixed spring, which compresses a distance x to stop
the box. If the initial speed of the box were doubled, how much would the spring compress in this case?
- correct answer ✔Twice as much. 1/2mv^2=1/2kx^2
You and your friend both solve a problem involving a skier going down a slope, starting from rest. The
two of you have chosen different levels for y = 0 in this problem. Which of the following quantities will
you and your friend agree on?
and answers 100% correct 2025/2026
For a race car on a banked curve, what force in general is producing the centripetal acceleration for the
car? - correct answer ✔Normal Force and Friction
Which is stronger, Earth's pull on the Moon, or the Moon's pull on Earth? - correct answer ✔They pull
on each other equally
The moon does not crash into the Earth because: - correct answer ✔Its high speed of revolution keeps
it from falling to Earth
Two satellites A and B of the same mass are going around Earth in concentric orbits. The distance of
satellite B from Earth's center is twice that of satellite A. What is the ratio of the centripetal force acting
on B compared to that acting on A? - correct answer ✔1/4 (F=GmM/r^2)
Satellites speeds up as - correct answer ✔orbits decrease
Energy - correct answer ✔Ability to do work
Can friction do positive work? - correct answer ✔Yes (box on moving truck. if box moves it is friction
doing positive work)
Catcher stops a 90 mph pitch in a baseball game? What can you say about the work done by the catcher
on the ball? - correct answer ✔The catcher has done negative work.
What is the work that the Earth's gravitational force does on the moon? - correct answer ✔None
because it Fd is perpendicular.
, What is the work done by gravity on a box not moving sitting on a flat plane? - correct answer ✔0
because the force mg is perpendicular to the distance it would travel.
A golfer making a putt gives the ball an initial velocity of v0, but he has badly misjudged the putt, and the
ball only travels one-quarter of the distance to the hole. If the resistance force due to the grass is
constant, what speed should he have given the ball (from its original position) in order to make it into
the hole? - correct answer ✔2v0 or double the velocity because Work=FDcos(theta)
Work=1/2mv^2-1/2mv^2.
-FD=-1/2mv^2
D=mv^2/2F
A 1000kg car travels at 10m/s. How much work must be done on the car to stop it? - correct answer ✔-
50,000J.
W=change in kinetic energy
-1/2*1000*10^2=-50,000
An object with mass 5kg falls down from a height of 5m. What is the change in potential energy for this
object? - correct answer ✔-245J
A box sliding on a frictionless flat surface runs into a fixed spring, which compresses a distance x to stop
the box. If the initial speed of the box were doubled, how much would the spring compress in this case?
- correct answer ✔Twice as much. 1/2mv^2=1/2kx^2
You and your friend both solve a problem involving a skier going down a slope, starting from rest. The
two of you have chosen different levels for y = 0 in this problem. Which of the following quantities will
you and your friend agree on?
