Answer:
The starting velocity for ball 1 is 1.00 meter/second. Its ending velocity is 0.25 meter/second.
The change in velocity for ball 1 is 0.25 – 1.00 = -0.75 meter/seconds
Answer:
P = 1097 Watt
Explanation:
given,
length of stairs, L = 130 m
inclination with horizontal,θ = 30°
mass of the football player = 105 Kg
time = 61 s
we know,

Work = change in Potential energy
h = L sin 30°
h = 130 x 0.5
h = 65 m
W = m g h
W = 105 x 9.8 x 65
W = 66885 J
now,

P = 1097 Watt
hence, the power output on the way is 1097 W
Answer:
5 m/s
Explanation:
Given that,
A vehicle is moving with 20m/s towards the east and another is moving 15m/s towards the west.
It is assumed to find the resultant velocity of the vehicle. Let east side is positive and west is negative. So,

Hence, the resultant velocity of the vehicle is equal to 5 m/s.
<h3>1)</h3>
No,kinetic energy cannot be negative since its given by KE=mv²,mass cannot be negative and the square of speed cannot b negative.
<h3>2)</h3>
Yes,any force opposing motion or displacement does negative work. They are often referred to as resistive forces (friction,air resistance,drag...)
<h3>3)</h3>
Nope it does not, it just forces the object to move in a circular path known as a centripetal force. It can accelerate an object by changing it's direction but not it's speed.
<h3>4)</h3>
No it cannot,If an object is sliding on the table (assuming it is not an incline), then most probably that normal force cancels out the weights effect or assuming there is an incline, it cancels the weight's y component.
<h3>5)</h3>

The work done is zero
<h3>6)</h3>

The work is just the product of the magnitude of the force exerted and the displacement of the object.
<h3>7)</h3>

<h3>Work is decreasing but positive</h3>
<h3>8)</h3>

<h3>Work is zero</h3>
<h3>9)</h3>

<h3>Work is negative</h3>
Answer:
a. 28.27 m/s
b. 12.75 m/s
c. No
Explanation:
a.
The bottom
Ek = Ep
¹/₂ * m * v² = m * g * h₁
v = √ 2 * g * h₁ = √ 2 * 9.8 * 40.8 m
v = 28.27 m/s
b.
At the top
Ek = Ep
¹/₂ * m * v² = m * g * h₁
v = √ 2 * g * h₁ = √ 2 * 9.8 * (40.8 - 32.5) m
v = 12.75 m/s
c.
No in this case the axis is the same of the motion so, the angle doesn't affect the result