Select the correct exercise category for each of the specific ways to increase intensity

The difference in a brass rod and steel rod is same as 12cm at all temperature .Find the length of the rod at 0°C.

egoroff_w [7]

Answer:

I think its 12 cm itself. Because in the question it is said that the length is same in all temperature

5 0

2 years ago

What force must the worker exert to get the box moving & what force must the worker exert to accelerate the box at 0.1 meter

photoshop1234 [79]

Since static friction is the minimum force required to just start the motion of a stationary object.

Here if we need to start an object from rest then we required F = 700 N

So for the first part of the above problem Force will be F = 700 N

Now if the box is already moving then we will have to use kinetic friction force between box and floor

now we can write the equation of net force as

$F - F_k = m*a$

here

$F_k = kinetic friction = 220 N$

$m = mass = 500 kg$

$a = acceleration = 0.1 m/s^2$

now we will have

$F - 220 = 500* 0.1$

$F = 220 + 50 = 270 N$

3 0

2 years ago

A skateboarder, starting from rest, rolls down a 12.8-m ramp. When she arrives at the bottom of the ramp her speed is 8.89 m/s.

melamori03 [73]

Answer:

a) a = 3.09 m/s²

b) aₓ = 2.60 m/s²

Explanation:

a) The magnitude of her acceleration can be calculated using the following equation:

$V_{f}^{2} = V_{0}^{2} + 2ad$

<u>Where</u>:

$V_{f}$ : is the final speed = 8.89 m/s

$V_{0}$ : is the initial speed = 0 (since she starts from rest)

a: is the acceleration

d: is the distance = 12.8 m

$a = \frac{V_{f}^{2}}{2d} = \frac{(8.89 m/s)^{2}}{2*12.8 m} = 3.09 m/s^{2}$

Therefore, the magnitude of her acceleration is 3.09 m/s².

b) The component of her acceleration that is parallel to the ground is given by:

$a_{x} = a*cos(\theta)$

<u>Where</u>:

θ: is the angle respect to the ground = 32.6 °

$a_{x} = 3.09 m/s^{2}*cos(32.6) = 2.60 m/s^{2}$

Hence, the component of her acceleration that is parallel to the ground is 2.60 m/s².

I hope it helps you!

7 0

3 years ago

A housefly walking across a clean surface can accumulate a significant positive or negative charge. In one experiment, the large

nalin [4]

Answer:

1681714.28571 N/C

Yes it could exist

Explanation:

m = Mass of housefly = 12 m

q = Charge = 70 pC

g = Acceleration due to gravity = 9.81 m/s²

E = Electric field

When an object accumulates charge it means that it is gaining electrons making it negatively charged. This is the concept of static electricity.

Here, the electric force and the graviational force will balance each other

$F_e=W\\\Rightarrow qE=mg\\\Rightarrow E=\frac{mg}{q}\\\Rightarrow E=\frac{12\times 10^{-6}\times 9.81}{70\times 10^{-12}}\\\Rightarrow E=1681714.28571\ N/C$

1681714.28571 N/C of electric field would be required to levitate

The direction of the electric field would be upwards vertically.

In air the critical value of electric field is $3\times 10^6\ N/C$ which is more than the critical value of electric field in air. So, the electric field can exist.

5 0

2 years ago

The brightness of a light bulb is most closely related to

vlada-n [284]

Answer:

a ) Its resistance

Explanation:

It depends on current and resistance

4 0

2 years ago