Could someone help me on #7?

A biker to move from speed of 0 m/s to final speed of 25 m/s in 10 s. What is the acceleration of the bike?

Rzqust [24]

Answer:

a = 2.5 m/s²

Explanation:

given,

initial speed = 0 m/s

final speed = 25 m/s

time = 10 s

acceleration of bike is equal to change in velocity per unit time

$a = \dfrac{\Delta v}{t}$

$a = \dfrac{v_f-v_i}{t}$

$a = \dfrac{25-0}{10}$

a = 2.5 m/s²

hence, acceleration of bike is equal to a = 2.5 m/s²

4 0

3 years ago

What is the amount of heat, in Sl units, necessary to melt 1 lb of ice?

likoan [24]

Answer:

Heat required to melt 1 lb of ice is 151.469 KJ

Explanation:

We have given mass of ice = 1 lb

We know that 1 lb = 0.4535 kg

Latent heat of fusion for ice =334 KJ/kg

Amount if heat for fusion of ice is given by

$Q=mL$ , here m is mass of ice and L is latent heat of fusion

So heat $Q=mL=0.4535\times 334=151.469kj$

So heat required to melt 1 lb of ice is equal to 151.469 KJ

3 0

4 years ago

IF YOUR GOOD AT SCIENCE THEN PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST

MakcuM [25]

Answer:

A: Copper is a good conductor

Explanation:

For an electrical current to flow through something, the main power source has to fight against the resistivity. Copper wire has a very low level of resistivity making it an excellent conductor. Basically, copper is super bendy and flexible, electricity.

Fun fact, sinc humans are also super bendy and essentially big sacs of all things wet and watery, we're considered to also be excellent conductors. We also have very intricate circuitry and a lot of natural electricity so basically, we were made for it, especially since the body already used little bits of electricity to function.

3 0

3 years ago

The take-up reel of a cassette tape has a radius of 2.5 cm. Find the length of the tape that passes around the reel in 7.1 s whe

Jet001 [13]

Answer:

s = 0.337 m

Explanation:

First, we will find the angular displacement of the reel:

$\theta = \omega t$

where,

θ = angular displacement = ?

ω = angular speed = 1.9 rad/s

t = time taken = 7.1 s

Therefore,

θ = (1.9\ rad/s)(7.1 s)

θ = 13.5 rad

Now, we will find out the length of tape:

s = rθ

where,

s = length of tape = ?

r = radius of reel = 2.5 cm = 0.025 m

Therefore,

s = (0.025 m)(13.5 rad)

s = 0.337 m

6 0

3 years ago

a spacecraft that seems to be motionless in deep space is given some type of quick push. which statement describes what will hap

bogdanovich [222]

An applied force applied causes a body such as the spacecraft to move. The magnitude of the force determines the change in the velocity

What will happen to the spacecraft is given by option C. from among the possible question options.

C. The spacecraft will begin to move and it will continue moving until it is stopped by an equal and opposite force

Reason:

The possible question options obtained from a similar question includes;

A. The spacecraft will move for some time then stop slowly

B. Air resistance will prevent the spacecraft from moving

C. The spacecraft will begin to move and the motion will continue until a force equal and opposite to the applied force stops it

D. The quick push will not cause the spacecraft to move, as a quick push works on Earth only

The state of the space craft = Motionless

Location of the spacecraft = Deep space

Type of force applied = Quick push

The statement that describes what will happen = Required

Solution;

Let F, represent the force applied, and let Δt be the duration of the applied force, we have;

The impulse of the force, F × Δt = m·(v₂ - v₁)

Where;

m = The mass of the spacecraft

v₁ = The initial velocity of the spacecraft = 0

v₂ = Final velocity of the spacecraft

Plugging in v₁ = 0, gives;

F × Δt = m·v₂

The space craft is given a velocity, v₂, and according to Newton's First Law of Motion, it continues moving in a straight line until another force acts on it

Therefore, the correct option is option C. The spacecraft will begin to move and the motion will continue until it is stopped by an equal and opposite force

Learn more about Newton's First Law of Motion here:

brainly.com/question/20841616

8 0

3 years ago