Motion in 1D
When a ball is thrown straight up what are the two key pieces of information you know at it's max height.
v = o and a =-g
Compare the time of flight for a bullet shot from the top of a building horizontally and a ball dropped from rest from the same height. Which one is greater?
They are the same
When you apply an upward force of
magnitude F to a block of mass 2.00 kg,
the block accelerates upward at 3.00 m/s 2 .
You can ignore any forces exerted on the
block by the air. Which of the following is the greatest?
Net Force
F
Weight
F
Bob pushes his sled up a hill. The conservation of mechanical energy will be valid here if:
Dissipative Forces are neglected.
i.e If Friction is neglected (including air resistance)
Which system is in a state of stable equilibrium?
A marble on a flat, level surface
A marble on top of a spherical bowl
A marble rolling down an inclined surface
A marble in the bottom of a spherical bowl
A marble in the bottom of a spherical bowl
You drop an object from a bridge and simultaneously, you throw a-other object downwards at 10 m/s. As the objects are falling, which object has the larger acceleration? (Ignore air resistance.)
They have the same value
An arrow is shot at a particular angle w.r.t to the ground to hit a target at the same height as it is shot from. Identify the quantities that remain constant during the time of flight of the arrow.
vx, ax =0 and ay =-g
How is does the weight measured by a scale on an elevator moving up at a constant speed compare to the actual weight of the person
They are equal
Use g = 10 m/s2. A block with a weight of 2 N slides across a flat surface with a speed of 10 m/s. What is the kinetic energy of the block?
10J
A feather and a bowling ball dropped on the moon falls to the ground at the same time. Why?
Lack of air resistance.
You throw a ball straight up and it goes up a height of a 10 m. How much should the velocity increase by to make it go up 40 m.
Velocity should be twice the initial value.
5 balls are shot from a canon oriented at angles 5,10,15,20 and 25 degrees with respect to the ground. With reference to the angle at which the canon is shot, which ball will have the longest time of flight?
The ball shot at 25 degree angle
A force of 20 N in the positive x‐direction accelerates an object giving it a = 2 m/s2. When the object is moving with velocity v = 10 m/s, an additional force of 10 N in the negative x‐direction is applied. What is it's acceleration now?
1 m/s^2 in +x
A boy holds a 80 N weight at arm's length for 35 s. His arm is 25m above the ground. The work done by the force of the boy on the weight while he is holding it is
0J
Explain why the work done by gravity on a bowling ball rolling along in a bowling alley is zero.
Fg is perpendicular to the displacement
You throw a ball straight up with some initial velocity. It takes 10 seconds for the ball to come down. How much should the velocity increase by for the ball to take 40 seconds to come down
Velocity should be 4 times the initial value
A ball is projected horizontally with speed 21.2 m/s from the top of a 24.3 m high building. Neglecting drag, what is its horizontal distance (in m) from the bottom of the building when it hits the ground?
Let g = 9.8 m/s2.
47.2m
A cart can move to the right or left along a horizontal track (the positive part of the x axis) as shown in the figure below. Neglect friction. A force is applied to the cart. Which of following graphs would be a straight line for the Force v/s Time Graph
(i) The cart moves toward the right (away from the origin) with constant velocity.
(ii) The cart moves toward the right and is speeding up at a steady rate (constant acceleration).
(iii) The cart moves toward the left and is speeding up at a steady rate (constant acceleration).
(iv) The cart moves toward the right, speeds up and then slows down.
4th one could but is not always the case
A motor operates at 100 W power rotating drum at a speed of 12.5m/s. What is the resistive force that the motor experiences.
8N
You drive a race car around a circular track of radius 100 m
at a constant speed of 100 km/h. If you then drive the same car around a different circular track of radius 400 m at a constant speed of 800 km/h, your acceleration will be how many time greater?
16
In how many of the following situations does the car have a eastward acceleration?
-- The car travels west at constant speed.
-- The car travels eastward and speeds up.
-- The car travels westward and slows down.
-- The car travels eastward and slows down.
-- The car starts from rest and moves toward the east.
3
A ball is launched up a ramp by a spring as shown in the figure. At the time when the clock starts, the ball is near the bottom of the ramp and rolling up the ramp as shown. It goes to the top and then rolls back down.
For the graphs shown below, the horizontal axis represents the time. Which of the following would be a straight line graph
(i) the x-component of the ball's position,
(ii) the x-component of the ball's velocity,
(iii) the x-component of the ball's acceleration.
(ii) and (iii)
An object's velocity in the positive x-direction changes from 4.7 m/s to 11.4 m/s in 4.1 s.
A force of constant magnitude 15 N is acting on it.
What is the object's mass in kg?
9.18kg
1200 kg car's speed changes from 20 m/s to 100 m/s in 4 s. By what factor does its kinetic energy change during those 4 s.
25
A Boeing 737 jet plane lands with a speed of 60 m/s (about 135 mi/h) and can decelerate on a wet runway at a maximum rate of 4 m/s2 as it comes to rest. What is the minimum distance needed before the plane will come to rest?
450m