Can someone please help me with some physics

Name two ways that friction is harmful and two ways that friction is helpful to you when riding a bicycle

lawyer [7]

Harmful

-causes heat; if it's not used correctly, it can cause injury
-when falling, the friction between your knee/leg and the ground can cause scrapes

Helpful

-helps stop the bike, the brakes rub against the tire which slows it down to a stop
-it can also help move the bike; the chains rub against tires which accelerate the bike

6 0

2 years ago

The amount of work done by two boys who apply 200 N of force in an

Aleksandr [31]

The amount of work done by two boys who apply 200 N of force in an unsuccessful attempt to move a stalled car is 0.

Answer: Option B

Explanation:

Work done is the measure of work done by someone to push an object from its present position. We can also define work done as the amount of forces needed to move an object from its present position to another position. So the amount of work done is directly proportionate to the product of forces acting on the object and the displacement of the object.

$\text { Work done }=\text { Force } \times \text { displacement }$

So in this present case, as the two boys have done an unsuccessful attempts to push a stalled car so that means the displacement of the car is zero as there is no change in the position of the car. But they have applied a force of 200 N each. So the amount of work done will be

$\text { Work done }=200 \mathrm{N} \times 0=0$

Thus, the amount of work done by two boys will be zero due to their unsuccessful attempt to move a stalled car.

8 0

2 years ago

The ratio of output power to input power, in percent, is called?

Harrizon [31]

That's efficiency. There's no law that it must be stated in percent.

4 0

2 years ago

Read 2 more answers

A bar magnet is dropped toward a conducting ring lying on the floor. As the magnet falls toward the ring, does it move as a free

Maslowich

Consider that the bar magnet has a magnetic field that is acting around it, which will imply that there is a change in the magnetic flux through the loop whenever it moves towards the conducting loop. This could be described as an induction of the electromotive Force in the circuit from Faraday's law.

In turn by Lenz's law, said electromotive force opposes the change in the magnetic flux of the circuit. Therefore, there is a force that opposes the movement of the bar magnet through the conductor loop. Therefore, the bar magnet does not suffer free fall motion.

The bar magnet does not move as a freely falling object.

3 0

3 years ago

A force of 2 kN is applied to an object to make it move 3.6 m in the direction of the force. Select the correct value of work do

vaieri [72.5K]

Answer:

W= F × d

W= 2kn × 3.6

W= 7.2 J

Work is measured in Joules!

4 0

3 years ago

Can someone please help me with some physics​

Can someone please help me with some physics