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4 years ago

When are magnets attracted and when are they repelled.

1 answer:

3 0

Magnets are attracted when each of the different sides, most commonly known as "North" and "South", are facing each other. They repel when North and North, or South and South are facing each other.

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2) What are the directions of the velocity and acceleration of an object in

zaharov [31]

Motion because the motion is the range

7 0

3 years ago

Read 2 more answers

John is going to use a rope to pull his sister Laura across the ground in a sled through the snow. He is pulling horizontally wi

bulgar [2K]

Answer:

The mass of Laura and the sled combined is 887.5 kg

Explanation:

The total force due to weight of Laura and friction on the sled can be calculated as follows;

$F_T = F_L+F_S$

= (400 + 310) N

= 710 N

From Newton's second law of motion, "the rate of change of momentum is directly proportional to the applied force.

$F_T = \frac{(M_L+M_S)V}{t}$

where;

$M_L$ is mass of Laura and

$M_S$ is mass of sled

Mass of Laura and the sled combined is calculated as follows;

$(M_L+M_S) = \frac{F_T*t}{V}$

given

V = Δv = 4-0 = 4m/s

t = 5 s

$(M_L+M_S) = \frac{710*5}{4}\\\\(M_L+M_S) = 887.5 kg$

Therefore, the mass of Laura and the sled combined is 887.5 kg

4 0

3 years ago

An open system starts with 52 J of mechanical energy. The energy changes

spayn [35]

Answer:

I think the answer is D,54 joules

5 0

3 years ago

A good conductor of electricity will also be a good conductor of heat because in both electricity and heat the conduction is via

almond37 [142]

Answer:Free-moving Electrons

Explanation:

In metals which are good conductor of heat and electricity metals are free to move.This facilitate the conduction of heat and electricity through them.In both case delocalised electrons is responsible for conduction as they are not firmly attach to particular atom and are free to move.

Heat conduction is due to vibration of ions in the lattice, at heated end ions vibration is much more as compared to cold end and this vibration passed on to heat the metal.

3 0

3 years ago

A flat disk, a solid sphere, and a hollow sphere each have the same mass m and radius r. The three objects are arranged so that

Aloiza [94]

Answer:

Explanation:

Rotational inertia of the sphere: $\frac{2}{5}mr^2$