Answer:
Deceleration, Distance And Velocity
<u>Explanation:</u>
- Deceleration explains the reduction in speed of the car before it comes to stop and it is opposite to acceleration.
- Distance explains the location of a person from its home and its unit is meter.
- Velocity explains the relative speed of an object concerning time.
- It shows both the "magnitude and direction" of the object.
- Deceleration and Velocity comes under vector quantity and Distance is a scalar quantity.
- Vector quantity shows the distance covered and the direction of the object
- Scalar quantity explains the distance moved by the object.
Answer:
0.91 J
Explanation:
The kinetic energy of an object is given by

where
m is the mass of the object
v is its speed
For the lemming in this problem, when he jumps, we have:
m = 0.0780 kg is the mass
v = 4.84 m/s is the speed
Substituting into the equation, we find:

Answer:
Both objects travel the same distance.
(c) is correct option
Explanation:
Given that,
Mass of first object = 4.0 kg
Speed of first object = 2.0 m/s
Mass of second object = 1.0 kg
Speed of second object = 4.0 m/s
We need to calculate the stopping distance
For first particle
Using equation of motion

Where, v = final velocity
u = initial velocity
s = distance
Put the value in the equation

....(I)
Using newton law

Now, put the value of a in equation (I)

Now, For second object
Using equation of motion

Put the value in the equation

....(I)
Using newton law


Now, put the value of a in equation (I)

Hence, Both objects travel the same distance.
Answer:
B) A stack of books is carried at waist level across a room
Explanation:
Work is defined as:

where
F is the force applied
d is the displacement of the object
is the angle between the direction of the force and of the displacement
From the formula, we see that the work done is zero when the force and the displacement are perpendicular to each other. Let's now analyze each situation:
A) A bookcase is slid across carpeting. --> work is done, because the force that pushes the bookcase is in the same direction of the displacement
B) A stack of books is carried at waist level across a room. --> no work is done, because the force to carry the book is vertical, while the displacement of the books is horizontal
C) A chair is lifted vertically with respect to the floor. --> work is done, because the force that lifts the chair is vertical, and the displacement is vertical as well
D) A table is dropped onto the ground. --> work is done, because the force of gravity (that makes the table falling down) is vertical and the displacement of the table is also vertical.