In which of these situations would there be the least kinetic energy?

If the velocity of a pitched ball has a magnitude of 44.5 m/sm/s and the batted ball's velocity is 55.5 m/sm/s in the opposite d

Yuliya22 [10]

Incomplete question as the mass of baseball is missing.I have assume 0.2kg mass of baseball.So complete question is:

A baseball has mass 0.2 kg.If the velocity of a pitched ball has a magnitude of 44.5 m/sm/s and the batted ball's velocity is 55.5 m/sm/s in the opposite direction, find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat.

Answer:

ΔP=20 kg.m/s

Explanation:

Given data

Mass m=0.2 kg

Initial speed Vi=-44.5m/s

Final speed Vf=55.5 m/s

Required

Change in momentum ΔP

Solution

First we take the batted balls velocity as the final velocity and its direction is the positive direction and we take the pitched balls velocity as the initial velocity and so its direction will be negative direction.So we have:

$v_{i}=-44.5m/s\\v_{f}=55.5m/s$

Now we need to find the initial momentum

So

$P_{1}=m*v_{i}$

Substitute the given values

$P_{1}=(0.2kg)(-44.5m/s)\\P_{1}=-8.9kg.m/s$

Now for final momentum

$P_{2}=mv_{f}\\P_{2}=(0.2kg)(55.5m/s)\\P_{2}=11.1kg.m/s$

So the change in momentum is given as:

ΔP=P₂-P₁

$=[(11.1kg.m/s)-(-8.9kg.m/s)]\\=20kg.m/s$

ΔP=20 kg.m/s

3 0

3 years ago

Can some one please help me with 7 and 8 I can’t fail this I’ll mark brainless .

Musya8 [376]

I think the first question is talking about the ionic compound Sodium sulfide and it’s formula is Na2S.
And for the second question, i’m pretty sure it’d be a positive charge

3 0

2 years ago

In an experiment, 108 J of work was done on a closed system. During this phase of the experiment, 79 J of heat energy was added

amid [387]

Answer:

187 J

Explanation:

First Law of Thermodynamics :

ΔQ = ΔW + ΔU

ΔQ : Heat. If it added to system then positive and if it is rejected by system then negative.

ΔW : Work. If it done by the system then positive and if it is done on system then negative.

ΔU : Internal Energy. If it positive then temperature of system increased and if it is negative then temperature of system decreased.

ΔQ = 79 J

ΔW = - 108 J

ΔU = ?

substituting the value in the equation:

79 = -108 + ΔU

∴ ΔU = 187 J

7 0

3 years ago

2. 3000. kg car is moving across level ground at 5.0 m/s when it begins an

gizmo_the_mogwai [7]

Answer:

yes

Explanation: Work is done when there is movement. Therefore it was work was being done.

7 0

2 years ago

A typical helicopter has four blades that rotate at 334 rpm and have a total kinetic energy of 4.55 105 J. What is the magnitude

djyliett [7]

Answer:

the magnitude of the total angular momentum of the blades is 743.71 kg·m²

Explanation:

Converting the angular speed into radians per second:

ω = 334 rpm · (2π rad / 1 rev) · (1 min / 60 s)

ω = 34.98 rad/s

The rotational kinetic energy of the blades is given by:

EK = 1/2 I ω²

where

I is the moment of inertia
ω is the angular speed

Therefore, rearranging the above equation, we get:

1/2 I ω² = EK

I ω² = 2 EK

I = 2(EK) / ω²

I = 2(4.55 × 10⁵ J) / (34.98 rad/s)²

I = 743.71 kg·m²

Therefore, the magnitude of the total angular momentum of the blades is 743.71 kg·m².

5 0

3 years ago