What are some common positive and negative attitudes toward physical activities? What

A calorimeter uses the temperature change of water to determine the _____ of another substance.

Evgesh-ka [11]

Answer:

A calorimeter uses the temperature change of water to determine the <u>specific heat </u> of another substance.

Explanation:

8 0

3 years ago

As part of his work for NASA, Dr. Murdock was asked to find out what percentage of people in the continental united States saw H

mario62 [17]

Answer:

Please, in the Explanation section you will find the explanation of the answer.

Explanation:

The exercise shows the continental United States and 3 cities used in the study carried out by Murdock. It can be said that the sample taken is part of the objective. There are several inconsistencies in Murdock's argument: the first has to do with the fact that the sample that was taken cannot represent the entire American population. A much larger, scientifically calculated sample would be required. The second is that their study did not take into account small cities or people living in the interior of the United States.

5 0

3 years ago

A ball has a mass of 1.5kg and is thrown straight up with a speed of 60m/s, what is the ball’s momentum:

madam [21]

Answer:

Assumption: the air resistance on this ball is negligible. Take $g = 10\; \rm m \cdot s^{-2}$ .

a. The momentum of the ball would be approximately $60\;\rm kg \cdot m \cdot s^{-1}$ two seconds after it is tossed into the air.

b. The momentum of the ball would be approximately $\rm \left(-45\; \rm kg \cdot m \cdot s^{-1}\right)$ three seconds after it reaches the highest point (assuming that it didn't hit the ground.) This momentum is smaller than zero because it points downwards.

Explanation:

The momentum $p$ of an object is equal its mass $m$ times its velocity $v$ . That is: $\vec{p} = m \cdot \vec{v}$ .

Assume that the air resistance on this ball is negligible. If that's the case, then the ball would accelerate downwards towards the ground at a constant $g \approx -10\; \rm m \cdot s^{-2}$ . In other words, its velocity would become approximately $10\; \rm m \cdot s^{-1}$ more negative every second.

The initial velocity of the ball is $60\; \rm m \cdot s^{-1}$ . After two seconds, its velocity would have become $60\;\rm m \cdot s^{-1} + 2\; \rm s \times \left(-10\;\rm m \cdot s^{-1}\right) = 40\; \rm m \cdot s^{-1}$ . The momentum of the ball at that time would be around $p = m \cdot v \approx 60\; \rm kg \cdot m \cdot s^{-1}$ .

When the ball is at the highest point of its trajectory, the velocity of the ball would be zero. However, the ball would continue to accelerate downwards towards the ground at a constant $g \approx -10\; \rm m \cdot s^{-2}$ . That's how the ball's velocity becomes negative.

After three more seconds, the velocity of the ball would be $0\; \rm m \cdot s^{-1} + 3\; \rm s \times \left(-10\; \rm m \cdot s^{-2}\right) = -30 \; \rm m \cdot s^{-1}$ . Accordingly, the ball's momentum at that moment would be $p = m \cdot v \approx \left(-45\; \rm kg \cdot m \cdot s^{-1}\right)$ .

3 0

3 years ago

How do the meetings of the words exercise and fitness differ?

ICE Princess25 [194]

Exercise is the activity and fitness is a lifestyle and done with time

7 0

3 years ago

The pulley system has a mechanical advantage of 5. Determine how much input force is required to achieve 1000 N of lifting force

olga55 [171]

Answer:

Input force of pulley system = 200 N

Explanation:

Given:

Mechanical advantage of pulley system = 5

Output force from pulley system = 1,000 N

Find;

Input force of pulley system

Computation:

Mechanical advantage = Output force / Input force

Mechanical advantage of pulley system = Output force from pulley system / Input force of pulley system

5 = 1,000 / Input force of pulley system

Input force of pulley system = 1,000 / 5

Input force of pulley system = 200 N

3 0

3 years ago