I need help for a review sheet

Which best describes most covalent compounds? O soft O brittle 3 O cold O warm

LUCKY_DIMON [66]

Answer: Brittle

Explanation:

took the test and I chose Soft, Soft is the wrong answer don't choose it. The CORRECT ANSWER IS BRITTLE

7 0

3 years ago

Which statement is a characteristic of a concave lens

Free_Kalibri [48]

"A concave lens is thinner at the center than it is at the edges."

If this isn't on the list of choices, that's tough. We can't help you choose the best one if we don't know what any of them is.

5 0

3 years ago

Which of the following are true about centripetal force? Check all that apply. A. Without centripetal force, an object cannot ac

Katyanochek1 [597]

B. Friction can be a centripetal force, such as when it keeps a car on the road going around a curve.

C. Gravity can be a centripetal force, such as when it pulls a satellite in its orbit.

Explanation:

The centripetal force is any force that keeps an object moving in circular motion, "pulling" the object towards the centre of the circular trajectory.

Several forces can act as centripetal force. Examples are:

- friction: when a car is going around the curve, is moving by circular motion. The force that keeps the car in circular motion is, in fact, the friction between the tires and the road.

- Gravity: when a satellite moves around the Earth, it is moving by circular motion. The force that keeps the satellite in circular motion is the gravitational attraction between the Earth and the satellite, that pushes the satellite towards the Earth.

The other two options are not correct because:

A) An object can also accelerate if there is no centripetal force (for example, a car speeding up on a straight road is accelerating, but there is no centripetal force since there is no circular motion

D) Centripetal force is not an outward force, since it pushes the object inwards (towards the centre of the trajectory).

3 0

2 years ago

Read 2 more answers

Consider an object rolling off of your lab bench. Discuss how you might be able to make measure- ments to determine its initial

guapka [62]

Answer:

measure the position every so often with a stopwatch

Explanation:

A possible method of measurement is to place a measuring tape along the path and measure the position every so often with a stopwatch, with this we can make a graph of position against time and by extrapolation find the initial velocity.

This is a method used in measurements of uniform movements of bodies

7 0

2 years ago

A ___ is a large ball of gas that generates its own energy. This energy is created by the fusion of ___ atoms to make ___.

Murljashka [212]

Answer:

Star, hydrogen and energy

Explanation:

A star is a large ball of gas that generates its own energy by fusing hydrogen atoms to make helium. It is held together by its own gravity. This process emits a tremendous amount of energy, and some of the energy is in the form of light.

The energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. When the core is hot enough, nuclear fusion commences. Fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

8 0

2 years ago